UMich has a horrible overcrowding situation. It started 5 years ago (my Fresh year) where the overadmitted by like 500 and lounges were converted into bedrooms and they put many students up in hotels. Its called build another dorm, we know you have the money too. And each year it gets more out of control.
As far as it relates to greek life, it seems the more they accept, the less that actually rush (the more that drop out of it too). Even though rush numbers are still good. It still amazes me though that they can get 900+ girls to go through.