Originally Posted by Fat Lucario_Guy
Don't know for sure yet, but so far there isn't anything to suggest Natural's presence in these games.
Aside from the fact that the Legendary Pokemon that N took in B/W is the one Kyurem stole energy from in the sequel.
Kind of a dead giveaway unless Game Freak is stupid enough to go "And suddenly Black Kyurem exists for no explained reason!" Which won't happen because they were milking B/W's story for all it's worth and I don't see any reason for them to stop now.