This thread can be closed now. Its obvious by taking one look at the Sun/Moon poster that Misty won't be appearing this saga or ever again.
Misty was written off 14 years ago and her cameos stopped 11 years ago in mid-AG. She's been gone 5 generations in a row. Its obvious to everyone she (or any other older character), won't ever be appearing. And this has been common sense for 10 years now.
If we were to use Common Sense as you put it, Charizard would NEVER have become an Oaked Pokémon (remember, he was gone for just as long, written off like she was, and even IF he were to return, chances were he would have gone back to Charcific Valley after the event he was needed for was taken care of, like with Claire, the Silver Conference, and Noland, and Brandon, yet BW changed all that by having him actually return to Ash's group permanently. If he could pull that off, Misty most certainly can, even you have to admit that.), and Jessiebelle would never have returned for DP either (and BTW, considering Jessiebelle was a COTD, which by definition was MEANT to be a one-off, that meant she had even LESS chances of reappearing than Misty, a former main character, did. Heck, in Jessiebelle's case, she had been gone for at the very least a full decade, if not a full dozen years.). So no, we still have a chance at bringing her back. Only time there's absolutely zero chance is if the show gets cancelled.
Also, I know a friend of someone mentioned that Mayumi Iizuka confirmed Misty would be coming back, so the point is moot. I still need to get the source, but as soon as I get it, I'll post it.
And those GEM figures were released around the 20th Anniversary of the Games instead of the Anime. If they were meant to be for the Anime's 20th Anniversary, common sense would dictate they be released next year, NOT this year. Not to mention, don't you think they would have released any figures of past figures beforehand if this had any precedent like, I don't know, during the 10th Anniversary of the Anime, or even the 10th Anniversary of the games?