What are the odds that the Big 12 regular season champion will get knocked out of a playoff spot by losing the Big 12 championship game next year?
If #2 beats #1, then the CFP committee will say "we couldn't decide who was better so we took (insert B1G/SEC team) instead".
If #1 beats #2, then the CFP committee could say "that second loss made team #2 drop, so both wins by #1 are lower quality so we took (insert B1G/SEC team) instead".
They're gonna take who they want regardless, because they can BS their way into justifying anything - there is always an argument to be made both ways, and they can pick whichever they want. And they are gonna take blue blood brands over worthy lesser names every time.