I think the Pac staying together does help Utah because it puts them in the playoff picture right away as one of the top performing (and now recruiting) programs.
At the same time, I can see the annoyance if the Big 12 jumps at Utah if the Pac folds. I believe Big 12 fans would love Utah and celebrate the invite...much more than the other 3 corners and the new 4. (Except for Arizona basketball.)
That would hurt. Especially if Utah came in and played well.