Its not exactly the same situation but I'm from the UK and live in Poland (because I'm a scientist and brexit happened). An enormous number of Polish people left to work all over Europe and the world since the end of communism, and I think its mostly been a massively good thing for Poland.
Most of the Polish people I know who lived abroad and have moved back to Poland have brought skills, often highly educated children, relatively large amounts of money, and what I would describe as an international forward thinking attitude (i.e. they aren't voting for PiS).
Its not inevitable that a lot of young people from the UK moving abroad is a bad thing for the UK, as eventually a bunch of them are going to come back.
That said all the flag waving bullshit I see the UK doing does put me off returning.
