They do and don't rely on tier of waitlist. My understanding is when someone withdraws an A, they try to match the demographics of the next applicant they pull from the waitlist. So if the only waitlisted applicant who approximately matches demographics is mid-tier, then a mid-tier waitlist gets pulled before a high-tier waitlist, but if a high-tier waitlist matches demographics too then they will be pulled first.Found out just now I'm also middle tier so giving this a bump since any insight at this point would be appreciated lol.