I wouldn't be surprised if KU told him he could transfer there and that a permanent spot on the team was contingent on how he looked in summer practices and workouts. I know he had a concussion and couldn't do much for a few weeks. Maybe the KU coaches told him he'd be better served moving along. KU's done similar things in the past. They will take a guy on scholarship with the understanding that it's only for a year and that they'll have to move on once they can fill the scholarship with a better player. There is a lot of talk that Marvin Begley, the #1 recruit in the 2018 class, is reclassifying and will commit to KU. Some are pointing to that as the reason for Jack's sudden departure.