There are other places he could play professionally if he wanted to forgo college. You are making the false assumption that the NFL is the only gig. If you are saying that he has a right to get a job immediately at the very top of his profession out of high school despite the qualifications set down by that particular employer, that is a silly argument.
The NFL has determined that a certain amount of time post-high school is a qualification for employment in their organization. So? Employers make these determinations all the time, and they have the right to do that.
He can go play in Canada or elsewhere if he wants employment. He doesn't
To have the right to the specific job with the specific employer he chooses. None of us do.
FWIW. Michigan doesn't seem inclined to get re-involved.