I believe there are three university campuses in MI, that do not have the legal requirement to acknowledge the CC permit (even if OC), it has to be voted on by the trustees of each university. U of M and Wayne State ae two of them (I think), can't remember at all the third.
MI has an odd law (might be a decision based on the laws) I would never take a chance on. If you go to a school (say to pick up your child), if you have the CC permit, you can legally carry OC at the school.
Not sure if there might be some federal issues to be concerned about.