Michigan will argue argue it, but I don't see a huge chance that they will win the argument. They have agreed to be bound by what the Big ten commissioner does. It would have to be way out of bounds for them to have a valid lawsuit. Even then, they would have a hard time proving something like 5 or 10 million dollars worth of damages which is nothing with respect to all of the universities that are part of the Big ten
The case may never get to court as the B1G will almost certainly move to dismiss as the case lacks merit because the B1G / B1G Commish has acted within their "Limits of Authority". scUM can't do that - note that the Commish met with B1G ADs prior to acting. Nonsensical to claim scUM has a strong case - a Hail Mary at best. The case has no merit under the law as scUM is a Member of the self-regulating Non-Profit it is suing and the Organization has done nothing outside the powers granted to it by its Member Organizations.