Are non-Unova Pokemon able to be traded to someone who hasn't beaten Black/White yet?

[totodileluigiolimar]

As I have asked others around various websites, I've been told that Pokemon that aren't from Unova can be traded to someone who hadn't beaten Black/White yet. One user answered this question and said it was possible. Just making a final confirmation, is it really possible that this sort of event can happen around if someone were to PokeTransfer someone else's Pokemon to their Black/White and trade it to someone else's Black/White who hadn't met the credits yet?