My absolutely uneducated guesses:
Incoming Rorie and Diallo.
Diallo will get a great amount of playing time immediately and probably for all four years. He doesn't project as a guy (Lee) who is thinking his next stop is the NBA so why not stay and get the most out of Cal? No way he leaves!
Rorie could be behind Singer as a PG. He could be behind Wallace. However, I think Wallace is better off ball, not as primary ball handler, and while Singer is solid, he's not scintillating. Rorie could step right not the position and own it for 4 years! After his transfer from Lincoln to Montverde and back, I imagine it makes all the sense in the world to keep it simple and stick with what he happily committed to long ago! I would be quite surprised if either didn't play a ton in Cal uniforms next year!
Remaining roster:
5 frosh to sophs:
Rooks and Moute have very little depth in front of them in Kreklow and Diallo. Wouldn't make sense!
Bird should be a front liner! No!
Matthews and Singer. It could get crowded, but both progressed and got playing time. Very doubtful.
Juniors Wallace, Behrens: Wallace is a 2 yr starter, so he wouldn't be leaving for playing time. Seriously doubtful. No need to, unless he hates the new coach and thinks he needs to develop for NBA in a hurry. Behrens has already used up a redshift yr due to injury so if he transferred, he'd lose a yr in playing time. Plus, he doesn't project to get any better playing time elsewhere. Get that degree! No way he leaves.
Senior Kravish, Kreklow: Kravish is headliner and student. No way. Kreklow has already transferred and would be done with eligibility if he transferred again. No way!
I don't see any reason for anyone to bail. The gates are open for them all.