Perhaps the SEC (and Texas/OU) saw the writing on the wall with CFP expansion.
Another lost detail in all this… Assuming SEC has been in talks w/Texas & OU for 6+ mos. as has been reported, the league’s insistence on a 12-team playoff (rather than 6 or 8) makes even more sense. That was the final piece to the puzzle to make the move palatable for UT/OU.
Under a 4/6/8-team playoff, where only conference champs get in, Texas & Okla have a competitive incentive NOT to join the SEC. But in a system where the SEC can put 6 teams into a playoff, well, go get some big money and be happy with an 11 seed.