I think it's standard, and I honestly also think faculty just don't know haha. During my interview, the one person said 3-4 weeks, then the other interview corrected them and said 2-3 weeks, and then the original person just said I have no idea. Hahaha. They said that faculty submit their lists, then GSE and the grad school have to approve those people and do some admin-y stuff, and then the notifications get sent out! So that's my guess why they probably just give some blanket "end of february" response!
@zh_hawk I bet your interview was ahhh-mazing! Every person in this forum could have been successful here, in my opinion. Sometimes it's just a matter of fit or timing.