Yes he is back, so they are 4 deep at that position. I think CU is the clear favorite over Nebraska, but I don't think that's how the public or books will view it. On one hand, it's in Lincoln and CU won't be able to count on 4 fumbles from Nebraska's QB. On the other hand, Nebraska's QB1 is likely going to be a true freshman making his second start, against a much improved defense over last season's CU D. Oh, and I also think Shedeur, Hunter, and a revamped OL (among others) will prove to be a much improved unit over last year.
Of course, I say this without really knowing who is all coming back for Nebraska's defense that was actually pretty solid last year.