(If you don't want to be bored by many paragraphs of source-text, skip to the conclusion in bold at the end.)
R. Joseph Albo touches upon the topic of future changes to the Torah in a number of places in Sefer HaIkarim:
1:3
We may also allow without difficulty the inclusion of Moses as the greatest prophet and the perpetuity of the law, because they are special principles, essential to the law of Moses which can not be conceived without them. For if we assume that there may be a prophet greater than Moses, it follows that the law of Moses may be abolished, for the words of a greater prophet should be believed more than those of a prophet who is inferior in degree, as we shall see later. Likewise, if we do not believe in the perpetuity of the Torah, we can imagine that the law of Moses may have been repealed after the Israelites were exiled from their land.
(Husik translation Vol. I p. 57)
Here he seems to have no problem with Rambam counting as a fundamental principle that the Torah cannot be changed.
1:15
The superiority of Moses and the immutability of the law we regard as neither fundamental nor derivative principles, because they are not essential to divine law. They are merely like branches issuing from the belief in the authenticity of the prophet's mission. If they are principles at all, primary or secondary, they are peculiar to the law of Moses, and not common to all divine law. Thus, belief in the Messiah and in the resurrection of the dead are dogmas peculiar to Christianity which can not be conceived without them. But the law of Moses can be conceived as existing without the belief in the superiority of Moses and the immutability of the law. It is better to say therefore that they are like branches issuing from the belief in the authenticity of the lawgiver's mission, and not independent principles.
(Husik translation Vol. I p. 136)
Here he seems to be saying that no one can change the Torah, but that it's not an inherent fundamental principle.
1:23
The third dogma is that the Law of Moses will not be repealed nor changed nor exchanged for another by any prophet. This dogma, too though it is not essential to divine law in general or the Law of Moses in particular, as we have explained above, nevertheless it is like a branch issuing from the dogma of the authenticity of the messenger, and therefore it is incumbent upon everyone who professes the Law of Moses to believe it, as we will explain in the third Book.
(Husik translation Vol. I p. 183)
Here he again seems to not allow for changes, but again notes that it's not an inherent principle.
3:13
He begins by arguing that changing the Torah is philosophically untenable:
We now desire to investigate whether it is possible that a given divine law of a given people should change in time, or whether it cannot change but must be eternal.
It would seem that a divine law cannot change, for reasons based upon a consideration of the giver, of the recipient, and of the law itself. Considering the giver, it would seem inconceivable that God who is the giver should desire one thing at one time and then change His will and desire its opposite at another time. It can not be that God should desire right at one time and wrong at another. Why then should God change His law for another?
Considering the recipient, we can not see why, since the nation is the same, the law should change in the course of time. We can not use the analogy of the individual and say that just as the rues of health for a child are different from those of a young man and those of a young man are different from those of an old man, as the time changes from childhood to youth and from youth to old age, so the rules of divine law must change with the times. For while it may be true in the case of an individual that his behavior is bound to change as the period of his life changes, the rule does not apply to a political group in which there is no such change from childhood to youth and to old age, for the convention of law is that all the times are the same. Hence we can not see that divine law should change by reasons of the recipient.
Now if we consider the law itself, it would seem that since the purpose of the divine Torah is to teach men intellectual conceptions and true opinions, there can be no reason for its changing at any time. For true opinions can never change. Monotheism can not be true at one time and dualism or trinitarianism at another, any more than it is possible that a thing that has already been should change and not have been. It seems clear therefore that there can be no change in a divine law, whether we consider the law itself, the giver, or the recipient.
However, he then spends the rest of the chapter explaining at length how it is actually not philosophically untenable for certain laws to be fitting for certain contexts. Then in Chapter 14 he gives various examples of changes that occurred and questions Rambam's proofs for the principle of immutability, and in Chapter 15 he discusses the rationales for the changes. In Chapter 16 he shows how none of the verses which appear to state that the Torah will remain as it is forever actually mean that, he gives more examples of changes, and concludes thusly:
There is nothing therefore to prevent us from supposing that the divine law may in the future permit some things which are forbidden now, like fat or blood or the slaughter of animals outside the temple. These things were originally forbidden when the Israelites left Egypt because they were addicted to the worship of evil spirits, and ate the flesh with the blood and also ate fat and blood, as we read in relation to the killing of animals outside the temple, "And they shall no more sacrifice their sacrifices unto the satyrs, after whom they go astray." But when this form of worship has been forgotten, and when all people shall worship God, and the reason of the prohibition will cease, it may be that God will again permit it. And some of our Rabbis have the same opinion. In "Yelammedenu" they say, commenting on the biblical expression, "The Lord looseth the prisoners" (מתיר אסורים), "He permits the forbidden" (מתיר איסורין).
To sum up, I see no evidence, nor any necessity, from Maimonides' arguments, that the immutability or irrepealability of the law should be a fundamental principle of a divine law generally or of the law of Moses in particular. This is also the opinion of my teacher R. Hasdai, namely that it is not a principle or dogma of the law of Moses. But he says that it is a doctrine which every one professing the Mosaic law should believe. The reason he gives is that if we examine all the parts of the Mosaic law, we find that they embrace all those moral qualities and theoretical ideas which are calculated to give perfection to the soul in some manner. This reason is similar to that which we quoted above from Maimonides' Guide. We will come back to the subject and inquire from a different point of view whether the Mosaic law is liable to change as are other divine laws or not. This requires some preliminary considerations.
(Husik translation Vol. III p. 147-148)
Here it sounds like he thinks that there is no reason for immutability to be a fundamental principle, but that it is still a good idea.
However, I think that the specific reference mentioned in the question may be to what he writes three chapters later. There he discusses at length the difference between the first two commandments and the next eight, and the difference between the Ten Commandments as a whole and the rest of the Torah. And he does differentiate between the categories with regard to a later prophet changing them. The chapter is quite long, so I will excerpt a few relevant passages:
Now as there is a difference between the first two commandments and the others in that the former were spoken by God without the mediation of Moses, while the latter, though heard from God, were explained by Moses, so we can say that there is a difference between the ten commandments and the other precepts in that the ten commandments were heard from God, whereas the others were commanded by Moses. And as we have found that the last eight commandments of the decalogue may be changed by a prophet temporarily, so we may say that the other precepts of the Mosaic law can be changed by a prophet even permanently. And it is for this reason that they could abolish counting the months from Nissan in the time of the second temple by the command of Jeremiah, as we have seen.
(Husik translation Vol. III p. 170-171, my emphasis)
Our opinion therefore is, as the matter appears from an investigation of the Torah, that one is not permitted to budge from his traditional belief which came down to him by a continuous chain of communication, going back to the teaching of a prophet, provided he is convinced that the principles, fundamental and derivative, of the belief in question are true, as we explained in the First Book of this treatise, unless he is absolutely certain that God desires to abolish the words of the prophet from whom the traditional belief came down to him.
The manner in which one can have this latter certainty is by having an absolute verification of the genuine character of the second divine messenger. The proof can not consist in the performance of miracles, since we see many other persons who are not prophets performing miracles either by creating an illusion or by magic, like the Egyptian magicians, or through some other art. Moreover, we find that those prophets who are not sent to announce a law also perform miracles, hence we can not tell whether the miracle performed by the person in question shows that he has been sent to promulgate a law, or whether it merely indicates that he is a prophet. It is clear therefore that a miracle is no proof that the messenger is genuine, as was explained in the eighteenth chapter of the First Book, but the proof must be derived from the law of Moses for the reason given in the eleventh chapter of the First Book. Accordingly, if his mission proved in the same manner as was that of Moses, it is proper to listen to the second prophet even if he desires to abolish the precepts of the first.
(Husik translation Vol. III p. 172-174)
Whether in the future there may come another prophet who will abolish the words of Moses and whom we shall be obliged to believe – this can happen only, as we have said, in one of two ways. either the new prophet will be proved to be greater than Moses, or his mission will be verified as was that of Moses. Now the Bible says that there can bot be a prophet greater than Moses, "If there be a prophet among you, I the Lord do make Myself known unto him in a vision,... My servant Moses is not so; he is trusted in all My house; with him do I speak mouth to mouth." It seems then that Moses' prophecy is superior to any other. And at the end of the Torah we read that there will never arise another prophet like Moses whom God knew face to face. This is the degree which Moses asked for and it was granted to him, as we read at the end of the Torah, "And there hath not arisen a prophet since in Israel like unto Moses, whom the Lord knew face to face."
(Husik translation Vol. III p. 175-176)
But if a prophet or one professing to be a prophet should come and say that he has been sent by God to promulgate a law, abolishing permanently the words of Moses, he must not be believed so far as concerns the ten commandments, since they were heard from God. But neither must he be believed in respect to the other other commandments outside of the decalogue, unless he can verify his mission as Moses verified his, when when all Israel heard the voice saying to Moses, "Go say to them: Return ye to your tents. But as for thee, stand thou here by Me, and I will speak unto thee all the commandment, and the statutes, and the ordinances, which thou shalt teach them."
(Husik translation Vol. III p. 178, my emphasis)
Hence they will not listen to any prophet who may come to abolish the words of Moses, unless they hear from God that he was sent for that purpose. For to obey a prophet and permanently violate a Mosaic command, is like obeying a prophet and violating that which one has heard from God Himself. In such a case one must not obey a prophet. It is for a thing of this kind that the prophet Iddo was punished by being devoured by a lion, because he obeyed another prophet and violated that which he himself heard from God. It is clear therefore that we must believe no one, whether he be a prophet or one professing to be a prophet, if he says that he was sent by God to abolish the words of Moses, or if he says that they are temporary and that the time has come for their abolition, unless his mission can be proved as publicly as the mission of Moses was proved in the presence of six hundred thousand people.
(Husik translation vol. III p. 179-180)
My own opinion is that since this does not necessarily follow from an interpretation of the biblical verses, it is more proper to say that this matter depends upon the will of God. According to the Torah it belongs neither to the category of the necessary nor to that of the impossible. Our position at present is that of a prophet who heard something from God. He must not listen to any other prophet who advises him to act contrary to the command he himself received from God, unless he himself hears to the same effect from God. And even if we can verify the mission of a new prophet as the mission of Moses was verified, we will refuse to listen to him if he bids us abolish any one of the ten commandments which we ourselves heard from God.
(Husik translation Vol. III p. 181-182, my emphasis)
From these passages it emerges that it is technically possible for Torah laws to be abolished by a subsequent prophet, under conditions that carry equal weight of those present at Moses's revelation, but even so the Ten Commandments are in a separate category and cannot be abolished under any circumstances.
3:20
It follows, then, as a result of what we have said, that since God granted Moses' request, as He said, "I know thee by name," we must understand the verse, "And there hath not arisen a prophet in Israel like Moses," to signify a permanent miracle sowing the superiority of Moses as a prophet to all the prophets who came after him. Therefore no prophet has the authority to oppose Moses' words.
Now it would seem according to this that the superiority of Moses as a prophet should be counted as a special and separate dogma of the Mosaic law, because it signifies the perpetuity of the latter. But an opponent may object to our interpretation. He may say, It is true that no prophet like Moses or greater than he will arise in Israel, but he may arise among the other nations, as our Rabbis say by way of comment on the verse, "He shall be exalted and lifted up, and shall be very high:" He shall be exalted above Abraham, and and shall be higher than Moses from which it seems that there may arise one greater than Moses. For this reason we regard this point s a derivative dogma under the principle of the genuineness of the messenger, and not as an independent dogma. Our idea is this. Granting that their interpretation is correct and there may arise in the future another prophet as great as Moses, we can not believe such a prophet or one professing to be a prophet in opposition to Moses unless we are clearly convinced of the genuineness of his mission. This means that his mission as the promulgator of a law must be verified in the presence of six hundred thousand people, as the mission of Moses was verified.
Whether such a thing will ever happen in the future, that all the people at once will hear the voice of God speaking out of the midst of the fire, as was the case with Moses – this is something that is hidden from us and can not concern us, as it depends solely upon the wisdom of God. But as long as a prophet's mission is not verified in this manner, we will pay no attention to any one who comes to abolish permanently the commands of Moses.
(Husik translation Vol. III p. 188-190)
But we have made it clear that there can not arise at any time another prophet greater than Moses or equal to him; and that it is not proper to listen to an inferior prophet at any time who desires to abolish the laws of his superior. But inasmuch as the opponent may obstinately insist that there may arise in the future among the other nations a prophet equal to Moses or greater than he, we did not lay down the superiority of Moses as a basic dogma, but only as a derivative dogma depending upon the dogma of the genuineness of the prophet's mission. The result is that we can not permanently abolish the laws of Moses at any time unless we can verify the prophet's mission in the way in which the mission of Moses was verified. Hence we do not have to regard the irrepealability of the Law as a main principle or dogma as Maimonides did. For we have made it clear that there is no evidence of it in the Torah. It is not therefore an independent principle, but a true belief, which depends upon the genuineness of the prophet's mission, as we explained.
(Husik translation Vol. III p. 190-191)
So, to conclude, it would seem that R. Albo did not say that the mitzvot will be abolished, as formulated in the title of the question, but he apparently did say that they can be abolished. However, even then there are strict conditions which make it unlikely that it will happen, and he does distinguish between the Ten Commandments and the rest of the Torah, arguing that the Ten Commandments can never be abolished even if the strict conditions are met.
We should perhaps note that R. Albo is not the only authority who allows the possibility that mitzvot will be abolished. R. Joshua Falk in his introduction to his commentary to the Tur writes as follows:
וגם ידעו ישראל על ידי זה שתורת משה היא נצחית ואין לשנותה על ידי שום נביא כל שאין אנו רואין שהש"י בעצמו ובכבודו חוזר ומתגלה במעמד ששים רבוא ליתן תורה חדשה על ידי נביא שיהיה כמשה רבינו ע"ה
And also Israel knew through this that the Torah of Moses is eternal, and we cannot change it through any prophet, as long as we do not see God himself and in his glory return and reveal in the presence of six hundred thousand to give a new Torah through a prophet who will be like Moses our teacher of blessed memory.
Thus, like R. Albo he apparently allows the Torah to be changed as long as it is under circumstances equaling those of the revelation at Sinai.
R. Abraham of Viterbo in the third essay of Sefer Emunat Chachamim likewise strongly criticizes Maimonides's claim that the Torah can never be changed.
