Why do you turn every "insert a new region here" speculation thread into a "Misty return speculation thread"? It's painfully obvious writers aren't going to bring her back even if the ratings drop to 0. Misty isn't even relevant to this thread to begin with.
In my opinion, while it is very unlikely, Serena has higher chance to go to Alola than Misty returning or Clemont/Bonnie staying. That card from Palermo could mean a bunch of different things. She also has 3 empty slots in her team to work with, maybe Palermo would be the informer to the gang about the next region. Who knows?
"Speculation thread." That's the reason. And since we're speculating on what will happen with Alola, we have every reason to assume Misty might come back especially with that
GEM figurine of her that was released .And don't give me the whole "she has no chance of returning." Neither did Jessiebelle and Charizard, yet they returned (Charizard in particular was even promoted to an Oaked Pokémon). Heck, Jessiebelle, if anything had even LESS chances of returning not only because of the long period of her absence (last we heard of her was in Holy Matrimony, nearly a decade before), but because she was Character of the Day, meaning she was bound to be retired after he debut episode.
@Horn: If they were truly through with the whole eyecandy issue, they would have kept Iris on the main cast for XY, NOT replace her with Serena. Had it been me, I'd make sure that there's absolutely no replacing the current girl at all specifically to AVOID any insinuations on eyecandy being the motivation of replacing the girl. Not to mention, they STILL haven't brought in the guy protagonist anyhow, even when they had the perfect opportunity to do so now that, if what you say is true, Masamitsu Hidaka is literally uninvolved with the anime now (maybe not in BW, but certainly with XY). Had it been me in the writers shoes, I would have capitalized on the vacancy Hidaka's departure left and make SURE one of the new cast members was the male protagonist for XY.
Also, Misty had a goal of trying to become the world's greatest Water Pokémon Master, a goal that, unlike the past lead females, she was NEVER given the opportunity to pursue on her own when she left. At the very least, bringing her back will ensure that Misty is actually GIVEN the chance to pursue her goal rather than, you know, being made into a punching bag by rookie trainers a'la Jessie and James. Heck, even Iris managed to pursue her goal when she left, and it being Dragon-types and it relying on village elders to determine aside, that was pretty similar to Misty's goal.
And in case you haven't noticed, Misty's returns barely had much arguing between her and Ash, and besides which, since she like Ash has an actual goal relating directly to Pokémon battling, she won't get stale (at worst, she'll only get as stale as Ash himself, as Brock doesn't even HAVE a goal relating to battles at all.).
And in case you haven't noticed, the 20th anniversary of the anime's coming up, so the writers actually have a pretty good opportunity to bring Misty back, especially when those G.E.M. series figures which included, you guessed it, Misty, that were released recently all but pointed at it (no reason to release them otherwise, especially when it's anime Misty they are dealing with, and while this is the 20th anniversary of the games, it's NOT the 20th anniversary of the anime), especially when the writers would most likely want to capitalize on that kind of achievement since it's pretty rare for many animes to last two decades non-stop.
EDIT: As far as changing her characterization, that's not likely, at least, not in the way you implied. In the two reappearances Misty had (three including Mastermind of Mirage Pokémon), her overall character was kept largely as is. If they were going to radically alter her characterization, they would have done it back then.
