There are several on D, but on the offensive side of the ball, yeah, you're really just talking about three players with this-year draft prospects. I'd have been surprised to see Evans go even before he got hurt, TBH, just because he's played relatively little. Alt's going, of course, and Estime will decide what he decides for reasons other than who is our OC.
But you do have a number of guys who could potentially transfer who would probably want to know more about next year's offense before deciding whether to go or stay. If you want to keep them around, you hire an OC quickly and then recruit the best transfer QB you can.