The NCAA can squawk all they want but all of this ultimately comes down to enforcement. Everyone in the sport knows ATM broke the current rules, yet nothing is done about it because the NCAA can't get hard evidence. How do these new guidelines change that? They don't. It was already illegal. Schools like ATM will still proceed the same way under the table and just wait to sign the official deal when the player enrolls.
Agree with others that there needs to be some kind of salary cap but it still comes back to enforcement. The NFL is actually able to enforce their salary cap. Idk for sure but I'm pretty sure they have the ability to pull private records (ie Tom Brady's cell phone that he destroyed). If Jerry Jones tried to pay someone an extra million under the table, it would likely end up in disaster for him. In college, there are too many boosters, uncles, trainers, etc willing to find under the table avenues of paying extra money, and no one has the power/ability to dig into private records to get evidence. Even if there's a salary cap, people will just cheat to surpass it.
So yeah, the only way this ever changes is if the schools grant the governing body, whether the NCAA or a breakaway, a lot more powers for enforcement.