Michigan's waitlist isn't ranked, it is just split into tiers. (And they can take someone off a lower tier before they "empty" the upper tier if they choose to do so.)
To a certain extent who comes off the waitlist depends on who decides not to accept their admissions offers. They don't necessarily try to do an exact exchange but, for example, MTdna you should generally be hoping that many in-state white males decide not to accept. If a bunch of OOS minority females decide to go elsewhere, then they'll likely accept a a similar demographic off the waitlist...
I do know that they said they're pretty thin on in-state offers at this point, so if any/many in-staters don't accept, some Michiganders on the waitlist are going to be happy.
Good Luck!