The maximum number of redundancies is stated in the S188 letter. The BA MOA states the selection criteria is LIFO, plus the redeployment agreement means a years pay per pilot. The best reason for keeping LIFO is that it makes the savings required much less to offset the most junior 1000 pilot salaries.
There has already been a considerable amount of PTW granted over CV19. Add in a few seniors about to go, and maybe a small take up of the RAF Deal, and the numbers come down even more.