That certainly would be an interesting plot twist. I'd be very interested in seeing how well that goes without the tax exempt status. As I've said numerous times, it's not even the institutions having to pay taxes, that would be a slight hit, but still be easy. It's the fact that the donations they usually get are no longer tax deductible for the donors. There is a reason that you don't hear about $10million dollar donations to the Chicago Bears so they can build a new practice facility or revamp their locker room.
Athletic departments losing tax exempt status isn't the game changer many think it is. Most AD's are losing money or operating on a small profit. If an AD that is making big money wanted to avoid taxes they'd just do what normal everyday businesses do (take extra depreciation, give bonuses to executives (coaches) and other legal means to reduce taxes).