What we definitely don't need is more Misty&Brock. I hate them. Their personality is annoying, and they are overused,and they got their proper ending. Don't go backwards recycling even more than the show notoriously does anyway. Btw, any interaction between Ash&Co is always welcomed, as Ash&Co almost disappeared during the Johto League seasons for havong no role, no personality, no interaction.
For your last wish: supported!
Overused? Hardly. Misty was in anime for around 5 seasons and during her time she didn't received nearly as much character development or fleshing out as she should had received. With many things about her story, dreams and personal fears and conflicts being left unfinished.
In comparison Ash or Rocket trio are in this anime for over 18 years, yet they still have many supporters wanting them to stay in anime and take through new directions being developed more(understandable in Ash case given how little his past and character are in reality explored).
Im flabbergasted when i hear how character which was in less than half of total pokemon episodes is called "overused". On what grounds?
Also Misty didn't receved closure to her story whatsoever.
She never became water master, never reached E4 level dreaming to become renowned water ace trainer like her idol Lorelei. Her future was completely uncleared taking over gym becaise of lazy sisters showing sadness and desire to leave in chronicles.
Hell even her romantic feelings were left hanging in air. Pretty much confirming in chronicles(i think it was episode "Date with Delcatty")when rejecting date with Georgio basically saying she likes someone else wuth writers leaving this un cleared and undefined.
If anything, out of replaced main characters Misty would be among those who deserve to return and get sequel to his/her storyline the most if you ask me. Given variety of subplots and options existing there to deliver original and creative arc.
EDIT:
Speaking of character dynamic i dont know what makes you think how Ash and co had "no personality or role in Johto".
Considering how Ash, Misty and Brock had arguably most organic, natural and spontaneous chemistry between themselves which gradualy became more consolidated and dappled with deeper uderlying dimension to their personalities.
As evidenced through less fights between Ash, Misty and Brock being replaced with more sarcasm and smart alec jokes passing their introduction phase being more supportive of each other, understanding of their flaws and much more attached to themselves). This was shocased through all of Johto such as Ash and Misty realizing their dependance on Brock domestic skills and wisdom showing great deal of care, motivation and concern when he was injured, sick por had love issues (like in
"Sick Daze!" or
"Heartbreak of Brock!"). Misty confining herself to friend Sakura how "Ash and Brock are her family she never really had until than allowing her to learn so much more about world" in episodes like
"Trouble Brewing!" or
"Espeon Included!". Showing lot of gratitude and love for them through worry when Ash was in danger, unbound moral support and encouragement and teasing or criticize but in less volent way beng done nmore ouzt of endearment than anything.
While their chemistry still containing lot of laugh, moral support, encouragement and moments of annoyance, clash between them truly having several memorable moments.
If anything you can notice in departure episode
"Gotta Catch Ya Later!" how much those three grew as friends compared to early Kanto days being heartbroken of ending separated.
Sure you can say how Ash and co got stuck in slumop of repetitivity and no real direction to go forward in middle of Johto once GS ball subplot was discarded with writers losing their main vector to push things firwqard taking sometime time to conso9lidate their thoughts and decide in what way to deelop characters and journey as whole.
But somewhere after Ecruteak city and starting with Whirl Islands anime became much more plot based with not just Ash, but Misty and Brock receiving genuine character development feeling like they have importance in anime again. Once Atsuhiro Tomioka took charge in planning out storyline.
Friendship between Ash , Misty and Brock obviously matured and became stronger. So it would be interesting to find out how they would function and interact between themselves if we ever saw them gathered together again having history and lot of memoroes they build together. Opening gateway to evolve their relationship in more complax way not being strangers anymore.
Especially with new roles and positions they are put in fulfiling requirement to deliver fresh, innovative way to do build up on their development and dreams they pursue.
The conflict here is, I believe there is no such title as "pokemon master". So closest thing to this imaginary title is being a Water Gym Leader.
Ash's dream is not to be a specific element's master, what a gym-leader is, that's why he is not turning into one.
You also confuse Ash's and Misty's goal. Ash want to win, while Misty wants to collect, train and research. Misty is simply told to quit being childish, grow up, take notice you already reached your dream. Ash'd need the same slap (unless he is still 10 years old which rises questions).
Position of gym leader doesn't make somene type masters being nothing else but headcanon with no facts to support such claims.
Both game and anime canon completely rebuke this claim. Especially when Misty was already Cerulean gym leader before meeting Ash going on journey to become water pokemon master and strongest water pokemon trainer in world.
Just like Iris is traveling to fulfill tasks and earn title of dragon master delivered from elders in dragon village.
Only difference is that water master and dragon master are showed in anime to follow completely different procedure and path in order to become one.
For record water pokemon master title exists:
Water pokemon master was stated to mean strongest water trainer in world wth E4 members being best type specialists in world. In both anime and games Misty worships E4 Lotelei wanting to become recognized and powerful as E4 herself.
Whirl Cup proved through talks of sea priestess Maya and prof. Elm from Newbark Town how winner of that tournament gets title "Alpha Omega of water Pokemon" being directly connected to water master title. Since sea heroes priest Maya talked about(which in Japanese version represent convoluted form of water master)were water experts knowing how to reach to hearts of water species communicsting with them and being used to full potential . With winner of Whirl Cup coming one step closer toward that dream.
In order to be water master you need to learn how to establish closer connection between trainer and water pokemon understanding their feelings, fears and nature. Learning how to use water specie to full potentioal. As prpoblems with Psyduck showed and mega evolution which allows pokemon to reach full potential.
Lastly term type masters unlike its case with much broader version of Ash goal(pokemon master)showed to exist in games as well.
Take a look at whats being said in fame checker about Clair or Lance. Mentioning dragon master title and how Lance grandfather is elder of famous clan of dragon masters.
Not to mention every E4 member in games is labeled as master of respective type it specialize in.
In fact XY games(Kalos)introduced water pokemon master better known as E4 Siebold.
