It's extremely hard to say... I like Collier from current rookies more rn than Flip, but Flip has the size and shooting potential that modern NBA needs. I think it'd be easiest to let go of offensive guards that I'll see no all NBA ceiling,so Brice for sure. Walker has great defense but I'm not very sure he'll ever build any kind of reliable jumper, but on the other hand, if his defense bounces back to rookie season level and above, and if he improves his offense a bit, they might regret.
So, in short, Sensabaugh for sure,let him go if asked for it. Hendricks will be very good imo when his shooting keeps improving, keeper. Cody, raw talent is obvious, keeper. I could let go Sensa, then Keynote, Collier and Walker after that.