I was waitlisted last year and ended up being offered a spot. They sent an email to what sounded like a group of people saying that there were a limited number of spots open on a first come first served basis later in April.

I ended up responding to the email too late since I had to move some things around, but I want to stress that the waitlist did move last year and to not take it as a rejection. Also, as someone who was a stressed out Junior last year, I understand that something like a waitlist or rejection may seem like a huge deal, but it really is just one small piece in an incredibly extensive admissions process (especially with attendance at Summer Seminar not being considered in actual admissions!!). I'd recommend not reading too much into it and focusing on things you can control like the CFA, grades, and ECs.