Looking through what KU's going to be losing this year to graduation. On offense, KU's not losing much. Bender is gone along with Sims, Booker, and Kerr Johnson, but there's still a lot of pieces coming back next year. KU only loses one starter on the OLine that has improved quite a bit from the beginning of the year and will only get better with another offseason.
Defense is another issue though. KU is losing just about every player in the front seven that started. I think the only DLineman and LB's coming back that played a lot of snaps are Azur Kamara at DE, and Kyron Johnson and Denzel Feaster at LB. The secondary is returning in tact and will definitely be the strength the of the defense next season.
There are a lot of returning pieces next season on offense, specifically the running game and with a coach who definitely favors a run first attack, I don't think KU takes a step back next year and may actually be better with Miles in charge.