Hypothetically when anime comes to end, i think this would be appropriate way to finish up anime, characters and their stories.
I still think it would make lot of sense and be really nice if for final season writers reunited Ash, Misty and Brock going on one more journey together having things come full circle with companions which started it giving them some more development, and tying up loose ends in their stories, later on bringing all previous companions for mini arcs like May, Dawn,
Iris etc wrapping up their loose ends in stories and getting some recognition for contribution they made to this show and Ash development influencing him quite a lot.
Afterwards i would like one grand finale where everyone come to support Ash for most important battles of his life, giving him moral strength and support of not being alone.
As far as character stories goes, something along this lines:
- Ash should either become or come very close toward achievement of his pokemon master goal. Prior to that he would already win league, defeat E4 and probably enter other regions, fulfill specific tasks like Battle Frontier was going on bigger and more requiring challenges until he become recognized as one of best if not best trainer in world.
I also think it would be fitting if he met his father who ends up revealed as very strong trainer serving as final and ultimate test to Ash skills as trainer,to show if he has what it takes to become master. It would be interesting to see battle between father and soin emphasizing on message of student surpassing teacher proving his skill and strength as trainer to others.
-About Team Rocket i could see Jessie,James and
Meowth after TR got disbanded somehow escaping arrest and prison. Knowing Jessie and James they aren't sure themselves what they want to do in life, going through soul searching through basically whole show. Jessie changed several careers, while James is too submissive and insecure as character to stand up for himself being in most cases follower doing what others tell him to do. I could see them trying to find what is their place in society and life.
-May would win Grand Festival becoming top coordinator and fulfilling her longtime dream, proving herself in coordinator world.
-Same applies to Dawn, and after she becomes top coordinator i could see her deciding to pursue different career(she did showed some interest in being pokemon stylist).
-about Misty, i think most suitable ending would be if she achieved her goal of water pokemon master going on journey to become recognized and strong water trainer following Wallace foot steps, or becoming E4 of water types. She always wanted to become strongest water trainer having high ambitions with E4 member Lorelei fascinating her claiming to be her idol, and i think it would be cool if such thing happened.
-Brock would become pokemon doctor and either open pokemon clinic or go on journey providing assistance in places where he would be needed.
-with Cilan i think it would make sense if he become S class connoisseur(he ius already A class not being far away), opening connoisseur shop or becoming one of evaluators which would test ourt young, aspiring connoiseurs in future.
-Iris should become dragon master proving herself to people from dragon village and other powerful dragon trainers, with
AXew evolving eventually.
-Max should age getting his first pokemon and starting out his own journey as pokemon trainer(perhaps even having promised battle with Ash for old time sake).
-Tracey perhaps going on some journey to research about new pokemon and regions enriching knowledge as pokemon watcher, eventually taking up Oaks place at ranch in taking care of pokemon on day.
This is what should happen imo.