Not fully up to speed on legal matters, but NIL stands for Name, Image, & Likeness Rights. Did not think the contract was for playing football or that NIL agreements were allowed to be contingent on a player attending a specific school. Sounds like Wisconsin owns his NIL for 2 years if they still pay him and they maybe obligated to do so.
If the player unenrolls at one school and enrolls in another one with eligibility normally, not sure what the basis would be for the NCAA declaring the player ineligible especially if the player properly submitted paperwork to enter the portal and the school refused to submit the paperwork on their end. The NCAA does not regulate NIL agreements or unless they are voluntary registered which Wisconsin refuses to do (not entirely clear to me how this all works).
Sounds to me like Wisconsin maybe paying this kid NIL while he plays at Miami or more likely they work something out.