I've often heard reference to the idea that a school had released a player from his commitment. I don't think they are required to, and they might be able to attach restrictions regarding where they can go. I think a coaching change is generally considered grounds to request a release (why would a new coach want to keep a player who doesn't want to be there?). While an established player would have to wait one year to play after transferring to another BCS school, I don't know how that would be treated for an incoming freshman who had not played yet. Since freshmen often redshirt, anyway, it might not make much of a difference. Someone on this board will know the rules.