I have a theory about Drexel. Please note that this is based on nothing but my own personal common sense.
Let's assume that last year your class was 30+ppl to large. So large, in fact, that you had to offer people $10 grand to defer. Now, note that this isn't really because they accepted more people, but because more people took their acceptances to Drexel. As such, I think this year, they will straight accept fewer applicants. What seems probable to me is that they would waitlist a larger number of people, give out fewer acceptances and pull people off the waitlist, who are much more likely to commit to go there. Instead of doing what schools usually do, which is to accept say 400 people for a class of 250 knowing that on average 62% of their acceptances actaully attend, it seems like they might be accepting less students, seeing how many people are actaully committing and then adding people from the waitlist. That way, the number they accept will be closer to the number that they intend to matriculate.
Remember though, this is just a theory, and I have no idea of their intentions.