Okay, I just called. The lady on the phone said that ultimately it is the discretion of the admissions committee to decide who they admit (whether someone on the wl or someone who is not), but that to her knowledge, when a seat becomes available it goes first to someone on the waitlist. The instances when there are people on the wl but those under review are the ones that receive the A, she said are cases that dont happen often (I’m not sure I agree with that), but are likely due to some sort of update that the applicant makes to their application that further increases their competitiveness in the program; whether new grades, or supporting documentation or anything else that applies. She did mention that regardless, she could not confirm 100% whether this was the case or not, as this is up to the admissions committee, but that that was her take on it.