Very excellent question.
I wonder if Saul would want it though? Or if they even bothered to ask? With Steve & Bean graduating (not to mention R Taylor being an option at point), the consensus with Simmons is how perfect it is for him to take a year and get acclimated before the starting PG and ample playing time opens up for him next year. Honestly I think I would prefer that, so as to capture more value out of his 3 years with us.
Now KK is a completely different situation, given if he doesn't get his waiver he will essentially lose his sophomore year.
Kenny can most likely seek a medical redshirt waiver for the year he missed at Michigan State. He was hurt.