The new NCAA rules are not profit sharing -- i.e., schools will not be paying players some portion of school revenue.
What it does is remove a restriction so that players can get paid for use of their names and likenesses.
For example, if EA Sports restarts the NCAA Football game, and puts players' likenesses and names in, they would be able to pay players money for that. Also, presumably, players could be paid for endorsements and autographed items.
Those payments would likely nearly all be coming from sources outside the school.
The NCAA wants to try to keep this from being a way for boosters to pay players to attend a particular school. It will be interesting to see how they try to prevent that.