Ryanair had to many bases to orderly organize them all efficiently. And now when the split crew and rule tactic no longer works it was time for a large cull.
Wasn't the message a month ago also that any crew that wanted local contracts had to go to the new Malta based subsidiary because the Irish government has refused even consultation on the matter of the policy that all Irish flagged aircraft have to have crew on Irish contracts that pay their taxes to Ireland. And hence that a lot of Ryanair aircraft and crew would be moved to the Malta airline. This could be a reorganisation preparation for this. Handily coupled with an opportunity to inject a bit of fear into the negotiations.