Lindz -- there are a few schools that do that. PNMs get to move in a few days early for rush and/or they are all temporarily placed in the same dorm during formal recruitment. So a PNM who's been dropped by all sororities has to spend the following day(s) surrounded by PNMs who are still rushing. Everyone else is getting prettied up for prefs, and she's got nowhere to go...
I much prefer the system we had at my school, where PNMs and other freshmen were sprinkled all over campus, mixed in with members of the other three classes, and there were plenty of other things going on during FR, so that a PNM who'd been released had other things to do if she felt like it, rather than having no choice but to mope in her room.