An astute poster noted the following:
Incumbent players have an exit meeting and find out what their role and “salary” will be for the coming season. Along comes a new player with a much higher price tag at their position, which via the grapevine the incumbent finds out about. That person likely presents his case to staff, while his camp puts feelers out to other teams. Feeling undervalued and underpaid if no counter offer, the player enters the portal.
So, it is not always a matter if a kid wanted out originally or the program preferred he move in, but just the transactional nature of transfer mania.