Agreed with Cyclone. Both games are different from a storyline point of view but... honestly without the background in B/W, the other games are a lot more confusing because it refers a lot back to the past, and having the older games are definitely an advantage, due to things like Memory Link (where you can connect your games), and so on.
However! This belongs in Quick Questions, so imma merge this there in case anyone else has anything else to add. :)