Do you remember if anything was said about waitlist movement? Do many of that 50% waitlisted get in as well?
I'm not 100% sure (schools are starting to get jumbled in my head) but I seem to remember him saying that there was some waitlist movement and it was dependent on which applicants declined their offer. Unranked, but if there was a niche a declining applicant would have filled, someone on the waitlist from that niche might be offered their spot.