well if they gonna add B/W2 then i have a question about it : do we have to do the story line all over again ?
You can get all gen 2 pkm so you don't need to get Johto and we still missing some gen 4 pkm so adding Sinnoh is better ( in my opinion).
Beside all of the feature you mention is already added to the game ( in the last 3 update)
3/6 in that sample r not in the game and U-turn only work in PVP so im not sure it is viable or not
and most ppl use Mienzhao Crobat for U-turn i think