That can't happen. The NCAA can't limit student compensation outside of the colleges and universities it governs. It would be the easiest lawsuit to beat the NCAA if they tried.
Your analogy is mixing the NCAA with the NFL. The NFL has a collective bargaining agreement under the NFLPA which is the player's union. There is no union of college athletes. That was proposed by athletes and the NCAA kicked that idea to the curb years ago. So, they opened Pandora's box when the could have sealed it shut.
Secondly, your mixing NFL compensation with endorsements. The NFL doesn't control player endorsements other than not letting them wear advertisements as part of the uniform and not during or after games.
NIL is about endorsements even if it's not carried out in the traditional manner. Every player is allowed to determine and obtain what their worth is in the endorsement world. That's free market and the Supreme Court ruled 9-0 for Alston in the case NCAA vs Alston which opened the door for NIL.