Just changed a lot.

So it's possible that BYU wasn't financially worth bringing in when the Big 12 had Texas and Oklahoma since BYU would bring down the average.

But without any change to BYU, BYU might now be bringing the average up. Also, even if they aren't bringing it up, it still might be a "best-of-a-bad-situation" kind of thing where adding BYU hurts the average, but at least keeps the conference in existence and is less bad than every other option