There will be a handful of undefeated and/or 1-loss teams this year.
Oregon, Alabama, LSU, Florida State, Oklahoma, Texas A&M, Michigan State, Penn State, Oregon, UCLA, Stanford, etc. etc.
I could make a gigantic list of teams that with 1 loss - or possibly even 2 losses - would get in over a BYU that doesn't blow out every single opponent left on the schedule.