"There they buried Yitzchak" — not "my father"?

Question

"What is awe" of a parent? asks Shulchan Aruch Yore Dea 240:2. It includes, SA answers, that one

shall not call [his parent] by [the latter's] name, neither during [the parent]'s life, nor in his death. Rather, he says "my father, my master".

Allow me to quote the Pische S'shuva :2, not to focus on his content, but, rather, merely as an example of how far this prohibition goes, how strict it is:

It seems to me that if others ask of him, "Whose son are you?", telling them "I am the son of Reb So-and-so" is permitted. Evidence of this [ruling] is from what the Maharshal wrote (in paraphrase):

That the Rosh referred to his teacher the Maharam of Rothenburg by name is all right, as he had multiple teachers and needed to clarify, but by one's father it's forbidden, as he has but one father [so can always say simply "my father"]. The fact that the Tur mentioned his father [by name] is okay, as he mentioned him in a respectful manner "the Rosh" which [besides being an acronym of his name] means "head", i.e. of all Jews.

Thus, if people don't know his father so he must mention him [by name], it's also okay.

(As always, for practical halacha, consult your rabbi.)

The very last thing Yaakov is recorded in Chumash as saying was (Vaychi 49:29–33):

I am [dying]. Bury me near my fathers in the cave in the field... that Avraham bought... as a burial plot. There they buried Avraham and Sara his wife; there they buried Yitzchak and Rivka his wife; and there I buried Lea....

Why did he refer to his parents and grandparents by their names, not even adorned with any honorifics?

(One can, as always, answer that, living before matan Tora, Yaakov was not obligated in any mitzva and therefore was not obligated in the mitzva of awe for parents. I am seeking meatier answers.)

Answer 1

This is discussed by R' Yaakov Tzvi Mecklenburg in Hak'sav V'hakabbala.

Originally, he suggests, as @Alex did in the comments, that it was permitted since Yaakov had already introduced them at his fathers in starting with "קברו אותי אל אבותי". However, because of other cases where we find this rule violated (namely, Bereshis 50:24 and 25:4), he offers the following explanation:

The reason that one generally may not call his parent by their first name is that a name in itself signifies a person as he was born; only through living his life can he achieve honorary titles. Thus, by calling a father by his first name, one is disrespecting him by implying that he has not achieved anything in his lifetime which deserves an additional dignified title.

When it comes to the avos, however, this is not the case. The names of the avos are intrinsically honorary. They were the names by which they were called by God and destined for greatness. Thus, there is no greater respect than to be called by these names, and the disrespect involved in referring to a father by his first name does not apply here.

Answer 2

I'll add that the Ben Ish Chai gave two reasons:

• Everything Yaakov said was said in ruach hakodesh, so he was required to speak in a very exact way, it wasn't just his own free way of speaking.
• Yaakov did say something like "my great, honored, father, teacher, etc.", but the Torah puts it down eventually as what is needed for future generations, in a shorter manner.

Rabbi Mordechai Eliyahu ZT"L went with the second opinion.

Sources:

• http://www.yeshiva.org.il/midrash/4157
• http://din.org.il/2012/01/09/%D7%9B%D7%99%D7%91%D7%95%D7%93-%D7%90%D7%91-%D7%90%D7%A6%D7%9C-%D7%94%D7%90%D7%91%D7%95%D7%AA%D7%9C%D7%A9%D7%95%D7%9F-%D7%A2%D7%A6%D7%9E%D7%95%D7%AA-%D7%99%D7%95%D7%A1%D7%A3/
• http://www.harav.org/Torato/ArticleDetail.asp?ID=264