ND's "auto-bid" is not all that it's cracked up to be. if my memory serves me right they only get 2 of the ACC's bids over the next 14 years or however long that contract is. they could max out this year and next and be stuck, and it's still not the AUTO-bid that being champ of the ACC would bring.

so what if a 10-2 ND is ranked #14 but left out. what if a 12-0 BYU is ranked #7 and left out of CFP but gets into Fiesta at-large? what if an 11-1 BYU gets left out? don't they BOTH have to get into a conference? B1G is full and spiraling way down hill. no sense in hitching your train to a train wreck. even though ND likes to consider itself an "east coast" school, they'd probably rather play in texas several times a year.

landing the country's biggest name program (ND) would be a huge coup for the Big12 as they'd boast the most popular college football brand and the most valuable (UT). BYU is obviously a solid add as well and it would solve everyone's problem with what the heck to do with independents. Army would be the only one left and they could join CUSA or something if needed. ND is also very close, geographically, to WVU. Big12 would get back to 12 and could split divisions like this:

North -
BYU, ISU, KU, KSU, ND, WVU

South -
OSU, OU, UT, TT, Baylor, TCU

you'd probably have to do 5 division games + 4 cross division games to get everyone into Texas each year + 3 non-con...not bad.

this really makes a lot of logical sense for everyone involved (BYU, ND, Big12, etc) so of course, it will probably never happen.