they say after peak 2008, but I don't think that even they know.
I just looked and counted 5 captains and 4 FOs leaving the 727 for the 747 classic. They all have decent seniority so the bottom dudes on the whale will be bumped.
Our contract stipulates upgrades before transitions, so by down bidding they gain an advantage when the next vacancy bid comes out. It allows them to bid what they really want as opposed to being forced to the leftovers.
It doesn't exactly do that. In fact, with original vacancies it doesn't do that at all. What it does do is limit the amount of recurring vacancies that happen after the original vacancy starts making seat changes. After one or two movements the recurring vacancy will go to an upgrader rather than a transitioning pilot. It is a little tighter even in the new deal than it was in the old.