My guess is that KO appreciates his alma mater at a level few, if any of us can fully comprehend. It is quite possible that everything he has accomplished, everything that he has is due to UConn and its basketball program (primarlily JC) and this is his way of saying thank you. I also believe thaat the $100k was quite a substantial donation considering everything as while he may have earned quite a bit under the standards of boneyarders, I would guess (considering the many ten day contracts) that he has not earned close to what many of his contemporaries have.
This, the character, grace, goodwill that he demonstrates clearly with this gesture is further evidence of the quality of a man our new head coach is.