By the time you win, your eligibility is up.If your scholarship is only good for one year at a time, how can your old coach dictate where you cannot go? I would sue.
So what?There are reasons to keep players from transferring to programs coached by former assistants as well as teams on upcoming schedules. The former is to prevent poaching, the latter is to prevent aiding the opposition (as well as saving the original school from possible embarrassment).