Maybe they are doing it geographically? I took the interview on 14th Jan but didn’t get the email or see the offer tab :/
Just my opinion but it might be better to stop worrying and obsessing about every possible explanation, given how little we know (and can confirm).
I'd assume they're sending admission offers on a rolling basis, so you still have a chance until they actually say "no". I'm in the same boat with CMU (probably worse as I haven't even gotten an interview invite).