Any coach should start the day after a season ends evaluating the talent for the next season. And any coach that promises anyone a starting role, specific amounts of playing time, or depth chart seating, is doing themselves, their players and their schools a dis-service.
If, under any conditions, DD told anyone that their position was open and that all eligible and would compete for position and playing time, I applaud him for that; particularly in a year when so much potential remained, just that, potential.
And any player who had, or has, a problem with that is expecting too much. It is called a team, and all have a role to play on it.
If the message and reception don't match, moving on makes a great deal of sense to me. I wish everyone leaving well, thank them for their commitment to MU while here, and hope that DD makes improvement in the overall results of the basketball in the coming year/season.