Probably more ways that things could go South, but lots of ways for them to get better for BYU.

A few examples:

Texas decides to go independent to make more money and others follow

New SuperConferences

Change in Political Pressure (the change from anti-gay marriage to pro gay marriage in this country happened extremely quickly...could there be a change towards BYU's standards?  I doubt it but you never know)

The top division separates and forces conferences to go to 16

New leadership in the Big 12 sees expansion as necessary

Some of these are more probable than others, but none of them are so far fetched to me as the Pac 12 expanding with Utah instead of BYU.  Yet that happened.