If she did that would be AMAZING, being interested in how much things have changed with original female. I mean we haven't seen her for very long time(since 2005 to 2006 to be more precise).
Since she appears in BW 2 games, Misty could have shot coming back and play important role as well since she is currently gym leader and is popular and iconic enough to warrant writers including her in anime again to bring boost to ratings and help advertize BW2. Not to mention writers left unfinished job about character and story, and update and more development wold be surely welcomed to get. In reality now is perfect opportunity to bring Misty and make her important again, because world tournament would not only b helpful to her story helping her to advance goal of water master, but it would also give writers on disposal all time favorite and iconic girl which could have been used to help promote new games.
Its wishful thinking, but i think if any saga was suitable for Misty return to cast this would be one of them because in that case with surprise return she wouldn't only bring unexpected twist to current series, but would also gain bigger marketing value to play in filler arc as well. She has quite a few things in common with Iris as well sharing passion for various hobbies like Cilan(fishing being one of them) so it would be fun to see how would Bw cast function with her . Giving character update and more development now that she is stronger taking her dream of becoming best water trainer in new directions wold be great to see as well.
Misty always wanted to become something more than gym leader, so leaving position to advance skills as trainer and become stronger like Wallace and other gym leaders which go on journey to learn new things would male lot of sense. And world tournament is perfect ticket to warrant her return.
Possibility of world tournament isn't so unlikely to happen when you think about it. There doesn't exist enough new gym leaders in filler arc after Unova and since there doesn't exist alternate quest Ash could compete in like it was case with first Battle Frontier, writers will have to look for something else to fill up filler saga.
And older gym leaders, E4 members etc returning in games for special tournament hosted by Cynthi could reflect on anime, with filler saga consisting of several arcs for which Ash older friends return.
Getting update on Misty character and what happened with her in meantime, receiving some development herself.
-To bring some humor and fresh character interaction within cast attracting more of older fans toward show. Going by past and Misty or May cameos in AG and DP they were one of highest TV rated episodes.
Its always nice and welcome when older character returns to see how he would interact with new characters and what kind of dynamic that would bring while possibly influencing other character story(like May did helping Dawn to get over self esteem issues).
It also imbues show with more continuity serving as nice twist and throwback to past.
To help promote BW 2 , since she matters to games again.
And to tie up unfinished things in story, having in reality room to be done much more. She didn't accomplished her water master dream, didn't came to fruition how to achieve dreams with writers putting her in catch 22 situation, leaving several things unanswered about character and its future.
Playing part in champion tournament seems like good step forward.
Besides if pokemon is still show about Ash journey being one big continuity it only makes sense to acknowledge past traveling companions existence and impact they left on main protagonist being important part of his life helping him to grow as trainer and contributing to anime popularity.
I don't think that's really problem. Most kids had no idea who Gary, Jessibelle, Butch and Cassidy etc were when coming back to DP series after years of absence and writers had no problems in reintroducing them and explaining to new viewers who they were.No but seriously. If they were to bring her back, the little kids would wonder who she is and what her history is, which would lead to confusion. The writers don't want anyone to remember her because they don't have the time or need to focus on someone from that long ago.
Im fairly certain good portion of today kids heard about Misty in one way or another.Several TV stations were or are airing reruns of older series giving to new generations opportunity to get know past companions.There is also internet,DVDs,older relatives from who they might heard of them,etc.Even if they don't know her it doesn't play much difference, because they would view past companion as basically new character accepting it .
If writers really want everyone to forget her they wouldn't provide references to Misty character though,by having her appear in DP "High Touch Opening",bring that lure of hers in Buizel episode along with being showed on picture in Brock special.
This was their way of letting audience know how character hasn't been completely forgotten and while unfortunately Misty still didn't returned in person for unusually long period of time, we don't know if writers have any plans to return her at some point.
Perhaps they are waiting for right moment,and i have hard time believing they will erase her completely from existence like she never mattered.That would be just wrong and disrespectful both toward character and fans.