Kansas's offense is legitimately top 20 in the country by FEI, and rated our 4th best opponent of the season (just behind SMU, KSU, and ASU). Kansas is fighting for bowl eligibility, and needs to beat BYU to get there. Furthermore, the top 10 ranking is a target on BYU's back, every remaining team is going to give BYU their absolute best shot. Formations and plays not previously revealed on tape, max effort, etc.
As awesome as the ending was for BYU's game last Saturday, the coaches and players cannot afford to let down even 1% in their film study, practice, preparation and effort if they want to continue undefeated.