The stupid thing, there is an easy and classy way to handle this. Just tell the kid "Of course we'll honor the scholarship. Also I'm introducing a new system and here are some ideas I had on how you can prepare for it." Said ideas can be a gentle nudge to convey "The odds of you getting playing time in this system are near zero." Then the kids can move on to new landing spot and no one's feelings are hurt.
Just get that message out within a week of your hire so the kids have time to reopen recruitment.