I don't wanna rehash this too much as it's old ground, but there are hundreds in BA, and the freighter outfit that became something else, has almost the majority EU pilots, Virgin has several, Ryanair, easyjet. All a very significant number. Over thirty years, I have worked equally on both sides of la Manche, and believe me, it's more in the UK by a big margin, pilot numbers were mentioned a while back, but prior to Brexit, in the general population there were three times more EU workers in the uk, than Brits in the WHOLE of the EU! (less now, after many migrant workers left in the last few months).
I can't think EU pilots holding UK licences are much chuffed by the situation. Just gotta hope BA VS etc can avoid redundancies.