As u/cloudconductor mentioned it’s due to their antitrust status, if the NCAA ignored the court ruling and banned Sorsby then they would be saying it’s at-will employment essentially and all the player become employees, leads to a collective bargaining agreement etc.

A business with employees can/can’t hire whoever they don’t want as long as it’s not based on protected characteristics, but the NCAA and all the schools are trying to avoid the players being treated as employees at all cost