First, all vacancies are awarded. Then the reductions are processed. Anyone bidding out of a reduced spot for a vacancy reduces that reduction in base/seat by 1. If you’re involuntary reduced, you can bid into ANY position your seniority can hold and in effect kick the bottom guy out. Even a bid with 200 Boeing CA vacancies and 200 Bus reductions will have large displacements because the Bus reductions are strictly in SFO and LAX, and the Boeing additions are spread over 4 bases. Maybe 5. Time will tell.
In any case, be ready for involuntary displacements and if you’re junior, bid ALL seats and bases you are okay with.