I could be wrong but my impression was that boosters offer NIL through their personal local businesses and usually worded in such a way that a departure by the student from the university would amount to the nullification of that contract. Car dealership in Ames can't expect to benefit from marketing with an Athlete based in Ann Arbor, so they would add in some protection in the agreement for the business. Of course the athlete is free to pursue other opportunities in his new location. I don't think the school itself is paying these amounts