The California govt already said they would fight if they try and leave without Cal. I don't think they would take Cal.
FSU isn't coming in as a non-AAU team. This AAU vote was a forecast of things to come. Maybe they don't take GT, and take Pittsburgh instead. But GT brings you the major GA market. getting into the Southeast is HUGE for the B1G to challenge the SEC.
Adding these 4 AAU teams Miami (3rd), GT (8th), UNC (23rd), UVA (12th) would give them every state in the top 12 of population besides Texas. Then you get the TV markets Miami (18th), GT (6th), UNC (9th), UVA (56th) That would be big for TV money covering that much population. The first push for expansion was states over certain markets because the B10 paid different based on teams within a state as a whole. Having the 11 of the top 12 most populous states would be huge for them.
https://www.infoplease.com/us/states/state-population-by-rank
The B1G isn't balanced now. Mich, PSU, MSU, and OSU are already in the lopsided east now, Last season it was 3,4,7 and unranked on the other side. Year before it was 3, 6, 9 and 23 on the other side.
I bet that the teams would want tradition more than balance. Adding ND into the Pod is important to them because they have decades of history with MSU and Michigan. PSU isn't going to leave the Pod without a fight as they have been with them for 3 decades.
And with the new playoff format winning the conference is not important.