You addressed the first one only, but most don't even know what the second one is.

1- A different approach by the coaching staff. Dave Rose bringing in Heath Schroyer and changing up the culture is the first.

2- And this one IMO, is at least as important and maybe a little more important, all of the losing last year. BYU lost a lot of games last year, and some of those losses were downright embarrassing. TJ Haws lost more games in his first year at BYU, than all 4 years of high school. Yoeli Childs won the State Title his Senior year of high school. Most of these guys weren't use to the type of outcomes they saw last year.
If not for all of the losing, especially the embarrassing losses, I know these guys wouldn't have been nearly as open to major changes as they were this offseason. Let's face it, losing sucks, especially when you are super competitive. When you're uber competitive, failure and the fear of failure will drive you and make you work longer than success will ever do.