I don’t think Jon pushed him out.
My guess is that yeah maybe Jeremy doesn’t have complete self awareness of himself as a pro prospect, but sometimes you need that self belief/ego to even be one to start with. There are plenty of instances that scouts (or in the business world investors) get wrong, and that chip on a shoulder can be a powerful motivator. Without it, it doesn’t make him as good as he has been at the collegiate level to start with. And maybe unlike at UNC, he’s tired of seeing everybody else go and being the lone stalwart and that irks at him and also unlike UNC where RJ is clearly the #1 option, he wants that for himself for once to prove what he can do and doesn’t want to be so overshadowed by Flagg. In any case, rationally it doesn’t make sense but he’s not mentally here for it then it’s probably better he move on. Sometimes people just can’t get over their own mental hurdles and a change of scenery is needed.
I’m bummed but it’s not hard to craft a mental narrative for him wanting to move on.