Re: Did the mass outbreak save Black and White 2?
I think having more Pokemon available (and especially choosing popular ones to include) was a big plus, but I think BW2 really needed more than that to be good. The addition of the medal system, ability to battle old gym leaders and new areas to explore really made it worthwhile to me. I was a little bit disappointed in the story just because it was so short and not much really seemed to happen throughout the game. I guess it was nice not to be bothered by bad guys every 5 minutes like on most other games, though.
Black and White were really the first games not to have Pokemon from any other regions available before the Elite Four. So while BW2 including other Pokemon was great, I didn't think it was such a big deal since that's what normally happens anyway.