Q. What is the Rov’s opinion about what it says in M”B 529: 19, that one is obligated to eat meat and drink wine on Chanukah, when in fact we know that there is no such obligation?!

A. Although Mishna Berura (ibid.) does rule that one who usually fast and abstains from meat and wine due to his efforts to do teshuva, on Shabbos, Yom Tov, Chanuka and Purim he has to eat. However, the dates are not all equal, since there is no obligation to do so on Chanuka, just a minhag, since after all Rambam mentions that there is a Rabbinical mitzva of simcha and joy on Chanuka.
On question 1222 we wrote: Horav Shlomo Miller’s Shlit’a opinion is that Chanuka is called a Chag and a Yom Tov as we find in Shulchan Aruch (Y. D. 217: 47) regarding a neder done exempting those days, that Chanuka and Purim are also considered Yomim Tovim at least in name. Taz (ibid. 38) explains that in the language and expressions that people commonly use, the are included.
Orchos Rabeinu mentions that Horav Chaim Kanievsky zt’l would indeed greet people with a “Gut Yom Tov” on Chanuka. See similar opinion in Alenu Leshabeach (6: p. 100).

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a