The collectives have not been disallowed. Because legally there's just no way to separate the collectives from "legitimate" NIL.
The very fist time the 3rd party consulting firm attempts to block an NIL deal from the collectives or anyone else, it's going to get challenged in court, and it's going to get blasted. Because without collective bargaining agreement from the involved parties, you just can't arbitrarily limit their earning potential.
The collectives aren't disallowed. They just have to show that the money they're paying out is commensurate with market forces. The collective cannot exist solely to collect money to pay NIL. That's coded in the statute. We'll see how long that statute survives.
For reference, what we've got is an "unfair restraint of labor" complaint. As a hand-waving argument, the NCAA said that players couldn't earn money outside the common scholarship stipend while playing college football. That kept the recruiting advantage sort of level (to those who followed the rules).
Problem was twofold: 1. Everyone else associated with college football was making insane amounts of money and 2. You couldn't progress to the NFL without passing through college football and the NCAA. In short, you were compelled to participate as an unpaid laborer in order to have a shot at a profession.
This put the NCAA in the exact definition of a "cartel" (not drug). There was no alternative to their services (no other road to the NFL), and they alone controlled the compensation. According to US labor law, cartels cannot exist, and must be dissolved.
Now, the NFL and MLB are also cartels, but they clearly exist. Why the difference? They are allowed to exist through special acts of Congress that authorize them with certain rules. That's what the NCAA "House settlement" is trying to achieve. Congress attempted to cobble together some equity rules that would allow the NCAA to exist while curbing the "no limit pot" pay for play that was the rule for the last 2 years.
The NFL and MLB have something the NCAA doesn't, but in my opinion, really needs - a players' union. The NFLPA and MLBPA are the players' negotiating arms for the labor rules with their respective NFL and MLB organizations. They set salary ranges, caps, insurance, work standards, contracts, and most everything else governing player and team responsibilities. Sure, negotiations can be ugly, but the result is a clearly defined set that all teams can agree is fair, and all players understand. The agreements will abide by the charters Congress set forth, and everything works.
As it stands, I don't believe the current "House settlement" will survive its first challenge. I agree with the spirit, but I don't think it will be deemed equitable.
