BYU would suddenly change their tune? They had from 2005-2009 to fix the TV situation and instead shouted BYU down every time they brought it up at conference meetings. That sounds like a recipe for a healthy relationship and that the conference would want to boost up BYU.
I don’t see how staying in a conference that hated you is somehow better for Big 12 expansion than taking more money, exposure and taking on better teams. BYU played the teams worth playing from the MWC as an Indy but also gave themselves a lot more chances to be noticed by playing Texas, USC, Wisconsin, Nebraska, Michigan State etc.
BYU wasn’t getting the G5 autobid. If it had existed when they were in the MWC, they maaaaaybe get it in 2001 with generational RB talent.
Indy wasn’t perfect, but it was better than the MWC, period.