It's one of the many mysterious about NIL. I have no fucking clue. I do assume that it's likely they're getting paid over time not a lump sum at once so my best guess is he keeps what he's been paid then doesn't get the rest. I think this comes up a lot when wondering what happens when a player transfers. I do remember hearing at USC and Florida and some other programs players talking about not actually getting the money they were promised or late etc so I think there's tomfoolery on both sides.
I would say one thing I've thought about which could be holding back contracts and more guardrails with NIL for stuff like this is say Program A says hey we will give you NIL but you have to pay it back if something happens or you portal etc but then Program B just comes in and says we won't do any of that, essentially forcing Program A to cave.
Your last point is the key to all of this. Collectives are going to get reputations over time.
Yeah and it's why actual rules and enforcement need to be put in place for all parties but I don't have high hopes. Even if rules are put in (they might actually be just not enforced), there's nothing to stop programs from just doing things illegally. It's actually why I don't have much hope for a salary cap type situation, which should be installed. I would think even the powers that be for the most part in cfb want something like that so they aren't forced to give out massive bags to not elite players just because certain programs offer unreasonable amounts of money.
Would love a system where players are getting compensated but still mostly going to the program they actually like and some kind of personality and regionalism can stay in the sport. Otherwise I'm probably out .