people, confirmed that it's B.S. Take a look at this recent DesNews article:

https://www.deseretnews.com/article/865693183/The-rise-and-fall-An-inside-look-at-the-decline-of-BYUs-marquee-sports-programs.html

Here's the relevant quote from Fehlberg:

“'I spent a lot of time working under cover of darkness to get us in the Pac-10,' Fehlberg says. 'It was a done deal, but it didn’t happen.'

The Pac-10 told Fehlberg that BYU would need a travel partner. Fehlberg suggested Utah, but the idea was dismissed immediately — BYU already brought the Utah TV market to the league. Fehlberg approached Colorado, which immediately liked the idea of joining the league. But, as Fehlberg tells it, Colorado later reneged. He says CU officials told him that Texas governor Ann Richards threatened to sue if Colorado left the Big 12, which included many Texas schools."

In other words, Fehlberg was trying to get BYU in with or without Utah, which is exactly what he should have done. There was no agreement between the schools about not switching conferences without the other. This also disproves the silly notion that BYU could have gotten in except for such an agreement with Utah. The whole narrative is absurd.