So, if Utah runs the table in the PAC-12, beating USC, Oregon, Washington, Cal, UCLA, etc, etc, etc, and then plays Michigan, Northern Colorado, and MWC team, do you think they are left out of the playoff?
Nope.
The rivalry is fun, but in terms of what Utah can accomplish, it is irrelevant.
That depends heavily on how the other schools do and the makeup of the committee. In short, Utah is dodging BYU in favor of a division 1-AA school because Chris Hill knows as well as anyone that anything can happen in a rivalry game. If Utah is ever championship-worthy they shouldn't have to make excuses to not play their in-state rival.