My point is that expanding this year would/could help the P5, not just BYU/Cincy. There are scenarios where it is 2 ACC and 2 SEC teams in the playoffs with the B10, P12 and B12 all left out. This would leave major debate given COVID. Teams are playing less games, thus small sample set to decide the top 4. At an expansion you will for sure get it the ACC, SEC, B10 and potentially P12 or B12. I would argue to bubble the teams to mitigate the risk around the playoffs (with bubble capacity going down 50% per week, not too tough).

...it will never happen, to be clear but IMO it would make many P5 conferences happy.

You are right, the risk to the P5 is that the expanded CFP goes too well and BYU/Cincy make a case of expanding permanently...heck lower tier P5 conference could have success and make a case (OU or USC). My gut says that BYU or Cincy get in with 8-12 teams in the playoffs and one/both get destroyed (ala Hawaii, Cincy etc) vs a Bama or Clemson....hammering home why these teams should not get to participate. We deserve a shot, but I am no where as bullish as many on CB that we could hang with Bama/Clemson (another discussion).