Because BYU is now a member of the B12 Conference...
It really doesn't matter what happens with conference realignment. BYU will be just fine regardless of what, if anything, occurs.
We'd all like to see the P12 conference implode, but whether it does or doesn't, BYU will be just fine.
We'd all like to see Utah eat some humble pie by staying in a diluted Pac or going to the MWC. But regardless of what happens to Utah, BYU will be just fine. Even if they end up in the B12. Even if (heaven forbid) they end up in the B1G.
BYU, finally, has the blessing of being in a P5 conference that appears to be stable, growing, and really wants them. They're currently in a really good place. Everything going on regarding realignment is just noise. It doesn't really matter very much to BYU.