@wiggy,
Yes, I agree there will almost certainly be areas of the industry shaken by this and I've heard the same from line pilots too. I have to admit its' certainly adding an unnecessary stress to my training as in my mind I see larger airlines having to shift their staff around bases to accommodate the rights of their workers. Or, in worst case situations, it could lead to redundancies - who knows!
Nevertheless, if British pilots all have to move home who knows what that would mean for available job positions in the UK. In any case, I'm hoping that through completing flight school within the next 12 months I'll fall on the right side of that employment window given Brexit won't really hit us hard until March 2019 when the full complete exit is expected to be complete.