are you asking how grandfather rights work?

If you are then it’s basically this:

let’s say you are a 97’ hire and prior to this mess you were a SFO 787 FO.
now let’s say I’m a 2015 hire and prior to this mess I was a SFO 320 CA.

I will get SFO 320 CA back before you can bid for it because you are a new entrant. Grandfather rights protect those who got bumped. It’s a great deal for some and a raw deal for others.

bid what you want want what you bid.