I'm not a spokesman for Utah football like KW or Chris Hill, but here's my take.
Utah football goals:
1) Win the PAC-12 South
a) if 1) occurs, win the PAC championship game
b) if a) occurs, win whatever bowlgame or playoff game opportunities result
2) Improve the program, grow the national stature, improve recruiting
3) Play 7 home games a year, if possible
Playing BYU does nothing to improve Utah's chances of winning the PAC-12 South. Playing Michigan and other B1G teams improves Utah's national stature.
I suspect there is sentiment within the Utah program to continue playing the BYU game, but it doesn't exceed the goals above (except maybe #3, possibly.) If playing BYU diminishes the prospects of the goals above (such as potential cheap shot injuries, which I think are unlikely), then the game loses its value.
With a 12 game schedule that includes now 10 league games (assuming B1G-PAC yearly matchup), Utah would want to schedule a "preseason" game, a can't miss win. See SEC scheduling for indication. With that said, and considering the goal of a 7 game home schedule, playing BYU yearly becomes more unlikely.