I wouldn't be surprised if this were the case. Basically, in prior application cycles, after a certain date (I think maybe February something?) schools were able to see all other acceptances held by applicants whom they had accepted. So for instance if you had been accepted at Wayne, MSU, and OUWB, once OUWB accepted you and it was after that date, OUWB would be able to see that you had also been accepted by Wayne and MSU. Having this data helps OUWB sort out how many acceptances they need. So for instance, they know that on average X% of people with 3 acceptances will come to OUWB. Or people from CA with an acceptance to a CA school have a Y% chance of coming to OUWB. Now these applicants are already accepted, so that information can't hurt them, but it does help OUWB determine how many more people they need to accept to fill the class. Without that information, they're basically making offers blindly and hoping they don't overfill. If you waitlist and accept slowly/later, you can always accept more people. That's inconvenient to the school and the applicant, but making too many acceptances too early is a disaster - you risk overfilling the class and needing to convince some people to defer a year, which I think has happened at another school recently if I'm remembering correctly. So I wouldn't be surprised if a lot of schools are more cautious with acceptances and more liberal with waitlists this year as a result.