There seems to be an assumption that if Coach wants Lieb gone, then Lieb must leave. Not so. The scholarship commitment was for four years. If Lieb wants to stay and get an Illinois degree, he can do it on an athletic scholarship, whether he plays or not.
That is correct, from my point of view.
But for guys that want to get minutes during games, a coach saying "I don't know that I can get you minutes next season" can motivate a player to move on to a new team. I am NOT saying that this is the case for Lieb, as he may indeed wish to stay anyway. I have no idea, nor is it my business.
What I am saying is that, as an example, guys with dreams of professional play, particularly the NBA (however realistic or not that may appear to us), hearing in April that playing time may not be available next season may decide that their best move is to transfer.