You never know how teams will be next season. No one had an inkling Minnesota would be 9-1 this season. Arizona State is starting a true freshman at QB and has several other young players. Michigan State you never know. Missouri you never know.
As far as Utah goes Huntley, Moss and Simpkins are gone. It's absolutely true that'll hurt them. You don't lose your all time leading rusher and one of the best playing QB's in the nation and not expect an adjustment. However, most of their skill positions return and they have a 2nd string QB who already beat us once and has a handful of starts and plenty of snaps under his belt.
It's not accurate to say they're losing all their offensive play makers. Far from it actually. They return an experienced and solid WR Corps and one of the better TE's out west in Kuithe. Covey returns from injury, but I'm not convinced he'll be what he once was. It could be argued on the offensive side of the football that we'll be replacing more play makers at the skill position than Utah will be. We lose Hifo, Simon, Shumway, Ty'son is a long shot to return, and most people won't be surprised if Bushman bails. Whoever our QB is will have to get used to several new targets.
Defensively they lose most of their secondary, Francis Bernard and their top 2 D-Tackles and Bradlee Anae, but if there's one thing Whittingham has proven he can do is re-load at those positions due to solid recruiting.