In the pesukei dezimra of each day we have a section of korbanot. On Shabbat, we add in a section which lists the extra korbanot of Shabbat. According to the Artscroll Yom Kippur machzor, we do that because "the verses of the Sabbath additional offerings...will not be read from the Torah." This explains why no special verses are added in for Yom Tov or Yom Kippur, as they will be read as the maftir of that day.
But according to my Artscroll sidur, we DO add in the text of the korbanot on Rosh Chodesh even though we will be reading those as the fourth aliyah in that day's services! Why would it then appear as part of the korbanot, defying the machzor's logic about why Yom Kippur's is not included? [the obvious answer being that the machzor's logic is wrong, but I am hopeful if that is the case, someone can explain further]
If one wishes to say that on a weekday Rosh Chodesh, the korbanot are not read as a maftir, but just as a fourth aliyah, this would still allow the question on Shabbat Rosh Chodesh, when the verses in question are the maftir.