I see this going one of two directions.
Either there is a players union that is formed. Every freshman gets a standard amount coming in, then they are able to negotiate their contracts in subsequent seasons.
Or some governing body (likely driven by the Big Ten and SEC) will form to provide some sort of rules and regulations.
But with the Supreme Court getting their hands on some of this, that can make governing a bit more difficult. Especially if there becomes some arbitrage where a public or private school has different rules or one state has advantages over another. Universities don't change the status or locations they operate, so there could be some inherent disadvantages for schools unless there's some form of regulatory body that standardizes the rules of conduct.