Misty DID NOT reappear in DP physically (she was only referenced once followed by her lure rod). Jessiebelle isn't a main character, so using her isn't a good example to your argument, same with Charizard, since Ash's previous Pokémon make appearances once in a while.
1. Jessiebelle was a COTD, which by mathematics have an even LESS likely chance of returning than a former main character (COTD = "Character of the Day", meaning they were intended to be one-offs). If she can return, then a former main character certainly can as well. Do you even know mathematics? When have we last seen Samurai, for example? Or heck, even AJ?
2. Charizard, however, in Johto and Battle Frontier, generally ended up leaving for Lisa's Charcific Valley once he's done aiding Ash. Best Wishes is the first time since he left for Charcific Valley that he actually rejoined Ash's roster, even going as far as to become an Oaked Pokémon. Not many other Pokémon have managed to pull that off (Squirtle, the only other Kanto Starter who actually left Ash's care instead of simply being Oaked, hadn't. And Butterfree and Pidgeot never even had an in-the-flesh reappearance since their departures, getting flashbacks at best).
We're also getting a May figurine too, does that mean May is coming back to the anime? Of course not, which is why using the Ash and Misty figurines is a poor piece of evidence. Your nostalgia for the original series is blinding you, weedle, and possibly your mind. I was emotionally depressed when Dawn got booted out, but I moved on, so why can't you?
It's not nostalgia, I have a near-eidetic memory, and thus cannot have my memories clouded. And while I can feel nostalgia (for example, I at times wish I could still be loyal to the Rebel Alliance instead of going to the Galactic Empire, but I know thanks to George Lucas' bombshell about the Rebels being VC members that I cannot actually be fans of them anymore), it's definitely not the case here. And as far as the figurines, I just checked Pokepolitan, under "G.E.M. Series", and there is absolutely NO mention of May in there, and in fact, there hasn't been ANY new additions to Pokémon figurines under the G.E.M. line since they announced Brock and Nurse Joy a little over a Month ago. The May figurine you mentioned, IF it even exists, is more likely of her game incarnation rather than her anime incarnation. Unless it's specifically under the G.E.M. line of figurines (which is pretty much guaranteed to be the Anime versions of the characters), don't try to refute that evidence. Also, the reason I'm focused on bringing Misty back is because, unlike Dawn who at least has the ability to pursue her goal, Misty wasn't even allowed to do so, because the writers and her sisters forced her to tend the Gym and be a punching bag.
EDIT: Thought so, the only May figurine that has been released this year was the Kotobukiya May, and it's pretty obvious it's NOT the May from the Anime, but rather, game May (especially when she was released around the same time Red's prototype was unveiled, and Red was obviously not an Anime character, and besides, the preview artwork makes clear that it's not Anime May in any way [if anything, it's closer to ORAS May]):
http://www.pokepolitan.com/2016/03/kotobukiya-may-red-prototype.html
So yeah, next time you want to refute my point regarding the figurine development, how about you actually use the same production line as my example, not to mention it being made obvious that it's in fact Anime May rather than Game May. I don't use the Bandai series Gym Leader Misty figurine as evidence that she'll return in the Anime, for example, precisely because even I know that that's not evidence there because Game Misty is NOT Anime Misty (even IF FRLG and HGSS gave her various character traits that referenced her anime incarnation, probably the only Gym Leader to actually do so in any way besides in Pokémon Yellow, since not even Brock got that), and besides, that figurine alongside the rest of the Bandai Gym Leader line was obviously only released for the sake of the 20th Anniversary of the games and thus cannot be used as evidence.
EDIT 2: I just realized something else as well: the announcer for the Princess Festival? He actually was present at the Kalos league's debut, meaning he just beat out Jessiebelle as the COTD who took the longest to reappear (actually, not even a COTD, a stock character), taking nearly TWO decades to reappear. And here's the thing, why would they reuse a character for one of Ash's important matches who, conveniently enough, actually previously appeared in one of Misty's matches. Seems suspicious, since they could have either created a whole new character from scratch, or otherwise brought in an announcer from the Indigo Plateau Conference, Silver Conference, Ever Grande Conference, Lily of the Valley Conference, or, heck, even the Vertress Conference.