My 21 yo son has dual British and Dutch nationality. Born and lived in uk, Dutch father. He’ll lose his Dutch nationality if in the next 10 years he doesn’t live in a Dutch territory or EU country.
I can envisage that he will live in Holland or the EU in that time, however if he doesn’t, he’ll have to relinquish one of his passports. Obviously it’s 10 years away and things change however if the choice was to be made now, which would you keep?