I think i'm a lil tardy to the party, but i wanna join in! I'm a huge Vampire Weekend fan and am quite familiar with all of them. I can seen him as an ENTP. I'm pretty sure that he is an extrovert from when he talks about his younger self, back in college. He was(and still is) very outgoing, and a pretty big party animal. He's really friendly and a people person. He does come off as pretty reserved, but that's probably just because he has a pretty busy schedule and is just so damn tired. Also, he could come off as reserved because of his chill, relaxed aura; but that's probably just what would qualify him as a P. I can see him as an introvert, but only in the way of him coming off as reserved, as I've previously explained.
As for the rest of them, i'm not quite sure, to be honest! There's not much revealed about them, but there is some that you'd need to search deep into the internet for. Rostam is an Introvert, i'm pretty sure of that. I*F*? INF*, maybe. CT is extroverted, i think. ESTP, maybe? I'm not sure about Baio..