To be replaced by contracts like other pro sports?
All IMO:
Even the powers-that-be running college sports - not a group with a reputation for insight and strategic planning - realize that NIL (which really isn't NIL) as currently constituted cannot survive much longer without collapsing under its own weight.
First brush, I would expect, would be some sort of revenue sharing (not like some of the pro leagues do it, per se, but in effect a similar system). May not be "players get X% of revenue", probably more like every program in the club pays $X million per year to their players (which gets adjusted every so often). I have some thoughts on how that will look - in its first iteration anyway, but that is a much longer story.
That will, by default, sort the entrants into classes - ie Power 5 vs Not, Group A vs Group B, or however one wants to phrase it - because you simply can't sustain a system with different entities working under different guidelines and expect there to remain any level of similar competition. (eg: SEC pays every player $150 K, but B12 pays $80K per player.... how long would that work before the two levels would simply have to separate from a competitive standpoint?).
The power resides where the $$$ resides - with the conferences - and, increasingly, with the labor force. Some number of them will need to find a way to work on common ground - without creating an unsustainable situation. Some will be "in", some will be "out",
May take an iteration or two to get there - but I think the final destination is pretty clear.... and it ain't this current thing that calls itself "NIL". That is simply not sustainable, IMO (so folks can, for the most part, do their dentists a favor and stop gnashing their teeth about it)