Hear me out. One of the reasons we aren't in a P5 conference is because of the honor code. The Big 12 doesn't care that we have an honor code, they just don't want the back lash of other people getting mad at the B12 for adding a school with a strict honor code. The back lash would include national media and bad publicity.
Buuuut, if UT and OU join the SEC and make a super conference, then the media won't be able to focus on BYU joining the B12 with their honor code. What is more likely to make the front page of ESPN. SEC forms a super conference and will dominate College football for years, or BYU has an honor code that no one likes and they joined the B12. The back lash would be significantly smaller with a major shift in Conferences.