If SEC+ACC+Big 12 go on to play

...and they are the only leagues to do so, this will radically change College Athletics for decades to come. The other leagues will either fall apart or it will take decades to recover. They'll be hit from 3 sides:

1. Current players will start looking to transfer
If you are a sophomore at a school like Ohio State, are you going to stick around in hopes that your school and conference grow a pair and play next fall? Or do you look to transfer to the SEC/ACC/Big 12 to ensure you'll get a chance to play in 2021?

2. Future recruiting classes will fall apart
You don't think SEC coaches will be telling the top talent in Ohio, Michigan, and California that they'll likely not get to play next season if they go to a Big 10 or Pac 12 school? Come to the SEC where you're guaranteed to play.

3. Schools who don't play in 2021 will take a major financial hit
The SEC/ACC/Big 12 will recoup 75%+ of the money they would have normally received in a typical year. Most comes from TV revenue or bowl revenue. The leagues that don't play will have to drastically cut their recruiting budgets and their coaching budgets. You're going to see Head Coaches going from $4 million salaries down to $1 million, etc. Do you think the best coaches are going to flock to the PAC 12 or BIG 10 for lower salaries? Nope.

And then this all trickles down to Basketball, Baseball, and Women's sports.

I've always been concerned that CFB would eventually become a regional sport. Now I'm afraid all college athletics will become regional sports.

Michigan and Michigan State basketball will never be the same. USC baseball will never be the same. Stanford will likely cut half or more of its smaller sports.