Who knows, but if they are senior they would have some decent two leg-two days on the Guppy. The plane sucks but they would have a great QOL. Beats a commute any way. We'll see I guess...
They should be concerned, management gives zero regard to the desires of the pilot group. If the numbers work out in their favor, they will absolutely move planes around.
Virtually none of my FOs has said that WB flying is a draw, I also dont really believe them if it pays more. Personally I'd love to do some international WB stuff at some point in my career. But I was acquired, not hired, so my perspective is not eskimo centric as I never even applied to them.
Worst case is they move them all to SEA. SFO/LAX have competition and management hates head-to-head. They like to avoid that. I would wager a high likelihood of half the WBs being based in SEA when the dust settles. I'm sorry but hopefully things change slowly at least.