I think NU will be staying in the B1G. However, if they left the fans would prefer the B12 again if they moved due to finding out it sucks to have no rivals and it is their best shot at long term competitiveness as their name still means something there. The money and stability would be with the SEC so it would have a great shot at them if they left, but they would really struggle to compete at all in the SEC going forward. They would struggle like Arkansas. They are currently struggling the the weak B1G west. That said I doubt that happens unless things get a lot more sour. Same with tOSU. Ohio State will only leave the B1G, if the B1G decides to not pay athletes.

NU left the B12 because it was unstable and they were not part of any moves that OU/UT were talking about. I don't blame them, but the move at the time was for stability more than anything else. They also probably thought that the move to the B1G would save their AAU status. They did get a pay bump from the current B12 contract at the time, but soon after the B12 got a better deal so NU will be making up the shortfall from their reduced B1G payout for a long time.

Nobody in the B12 harmed NU's academic brand. All the B12 AAU schools, including Texas, voted for them to remain in the AAU. The B1G schools actually led the charge to boot them from the AAU and even then it was NU's fault. They were warned 10 years prior that they needed to move their Med school from Omaha's umbrella to Lincoln's or risk expulsion. They ignored it and got stung.

Their football brand got diminished because their walk-on program got marginalized and the academic non-qualifiers were eliminated in the B12 by an 11-1 vote. They used to get their lineman from the walk-on program and their skill position players from the academically questionable. Now going 1-9 versus Texas was humiliating and part of the reason they left was definitely that OU/UT was way ahead of them at that point as programs.

NU voted for the financial structure of the B12 at every turn. They just unfortunately regressed in football to the point that they were usually #4-#6 in conference revenue payouts behind OU. UT, and KU most years rather than being at the top like they were in the 90s. They also voted against a B12 network (I think UT was the only one that voted for it) and were already developing their own network before UT created their own. They dropped it, of course, when they went to the B1G who had a network.