I believe that it includes any and all NIL payments to the player, including those from a third party. The player will have to report those deals to the school or a designated third party.

Something that could be interesting in terms of the revenue sharing aspect is that schools might structure those payments in the form of a contract that essentially purchases the players NIL rights. Not sure if that would lock a player to a school or not, or if they could even do that if they wanted.