Some of which will be popular to note on this board ..and some of which will be less popular

1. (The popular truth): BYU has been playing an independent schedule for the last decade. It's not been a P5 quality schedule, but it's been more than a typical G5 schedule. So the transition should be easier.
2. (The unpopular truth): BYU is going into a lesser conference than Utah was.  The PAC has obviously fallen off a LOT since, but when Utah arrived, it was one of the stronger conferences. USC with Carroll/Kiffin, Stanford with Harbaugh/Shaw, Oregon with Chip Kelly/Helfrich.  The PAC eventually fell off, but the current Big 12 (made up the least desired remnants of the conference and a bunch of recently promoted G5s) is less challenging than the situation Utah came into
3. The transfer portal makes change faster.  It used to take until the 4th season to have turnover to reflect a new conference. That can be a lot faster now (though it won't necessarily always be the case)