A quick glance tells me that only the top two or three 75 FOs can hold WB or 75 CA and the top 15 should be able to hold 72 CA.

But, they could've held those seats on previous bids. I expect most of that group of 75 pilots to stay put.

It'll be the lower portion that tries to go to the 72 FO seat. Everything else will depend on the 50-60 72 FOs that can hold 72 CA. If they upgrade, it will free up some senior 72 CAs to move.