I’m not sure what you are getting at. When Utah moves to Big 12, previously scheduled non-conference games against Houston and the parochial school become conference games so Utah needs to fill out the non-conference schedule.
However, even if the Pac-12 had stayed together something was going to need to change on the 2026-2028 schedules because you would have 12 P5’s, 11 P5’s and then 11 P5’s due to those two schools moving up a tier. Either way you slice it, the conditions had changed since the scheduling agreements were made.