I doubt Misty will be considered for a return. There's just a bunch of other characters that could be brought back that would make more sense than Misty,
I would certainly welcome a comeback from Misty in BW2...She's actually involved with the World Tournament in the games, and it would tie in nicely as a continuation of her goal in the anime.
Even if she did show up, it'd just be for a cameo. But she is just as likely as Brock or any other gym leader to show up; honestly, I would say that Brock is more likely. The World Tournament is honestly the only way she'll show up again, but don't expect some big fanfare and angels singing in the background and her returning to the group or any Pokéshipping crap; if she does it'll be with Brock or some other past character, she'll be all "hey Ash" and he'll be like "hi Misty" and they're not going to start making out or something, and she'll reveal she caught some random water-type. Then she'll battle, lose to Iris or Cilan or even Ash, and leave. That's it.
But a cameo from Misty is about as likely as a cameo by May or Max, so...
I agree with above poster how Brock would have higher chance, if anything than because he didn't made regional cameo yet. But from practical standpoint Misty would be more suitable candidate to come for World tournament than Brock in reality could, solely because she is actually gym leader and trainer by profession which would actually gain something from entering such prestige competition following game canon.
When you think about it BW2 games offer something enough big and substantial to allow to bring Misty even for temporary return to cast staying for whole filler arc or extended cameo appearance like Dawn does. If there are more tournaments not stopping just on Junior Cup, its not farfetched to expect Misty leaving gym like other leaders do traveling through Unova filler arc to enter tournaments host by Cynthia to develop new battling style, advance her goal of becoming water master(this would help her to progress more than even Whirl Cup did)and learn new things by battling best. She could also catch new water pokemon native to BW region enriching her team ad i believe her presence as fourth companion for awhile would add new life to main cast with her fiery and snarky personality, making things more interesting.
We don't know if and for how long she might return, but if there ever came out opportunity to do with Misty character something more significant than just occasional cameo than i believe im not mistaken when i say how BW2 is best opportunity we had in long time to do so. Judging by huge demand for return, this would help ratings too which could use some boost after decline which happened not so long ago.
Because of popularity, untapped potential and impact she left on anime if writers ever decided to make past female important again and return for some important role, Misty will always be among first candidates on the list regardless of some will say.
There is no reason why writers wouldn't bring her back in BW2 and capitalize on character popularity.
That's the way i see it.
I think all of them need to make a return, even Dawn again even if she all ready is making a return. They need some episodes were Misty, May, Dawn and Iris go on their own adventure ( and maybe talk about who what type of guys they like) while Ash trains with his Pokemon, and Brock and Cilan compete about who is the better chief .
Because she only return shortly in Advanced Generation series, that doesnt mean that she is going to return in Unova because she is currently a gym leader and her sisters are probably still traveling across the world, and like Misty, May returns in Diamond and Pearl series and now Dawn.
The chances that Misty is coming back to Unova to support Ash in Unova League are 5%, but Dawn chances of supporting Ash in Unova League are 95% and May chances are 0% because she is probably now a Top Coordinator in Johto and is training back at her home.
no everybody knows that the only chracters who return are those from the past saga hence Dawn returning but Misty lol no