It does happen a lot. The first thing Tambroni did when he took the Penn State job was to release all the commits and he told them he may or may not recruit them again. That should serve as notice for any HS underclassman who commits to UVA or another program where the coach is headed out the door. It also happens a lot more than people think when kids decommit here and then commit there. This can be a family just upgrading from a Furman to a UNC but just as often it is a kid who is getting a signal that he's not lined up well anymore to get the earlier promised scholarship and he should consider looking into other options. That is a polite way of saying you can come here and walk on but that may not be in your best interests.