I think so.To play in a international sport not for your nationality team, dont you need to have lived in that county 4 years?
Personally, I don't think you should be allowed to play for one country if you've played for another up to a certain level. For example, if an U16 Aussie moves to the UK, he should be allowed to play for England. However, if he's played for Australia A, perhaps he shouldn't?
There are always exceptions, but these should be on a country-by-country basis. For example, if Wales became a separate cricketing nation in its own right, they can have Geraint Jones