Well he has consistently done better in leagues over the years, top 16, top 8, top 8, top 4 then win, and he won orange island league (although that isn't a great league)
sun and moon where he won the league. xy is the previous season where the studio behind the anime started doing more 3d animation. and in sun and moon just kept perfecting it
And so now he will have to circle again the planet but this time counter clockwise, up in the clouds (one piece style), he will loose all of his pokemons and will start again from zero with another type of creatures called Pekomons (bleach style), Pikachu will become a chuni-emo (with the full package : obsessed by the power of "his cursed eyes", ridiculous haircut, tears of blood, way to much black eye liner, an unhealthy interrest for crows, doing stupid stuff while making weird poses, having a new group of "cooler" friends that are all somehow stupider than the others) and will become Ash worst frienenemy (naruto style) or he will discover that all of the know continents he visited are just a tiny archipelago, less than 1% of the total landmass of the planet, and will have to explore everything else because all he did so far was worthless, and the serie will go in an undeterminated length hiatus (HxH style) ?
we'll see if satoshi will be in the sword and shield anime. if yes, then i think it will be a new story to pursue. champion of a league is not a pokemon master goal
YUSSSSSSSSSSS LOOKS LIKE ASH IS DESTINED TO WIN ALL ISLAND CHAMPIONSHIPS (orange and alola) THE NEWS THAT ASH WONT BE THERE NEXT TIME IS TRUE I swear I hope the next anime goes for either generations style a slice-of-life style focusing on pokemon or random trainers Pokemon adventures manga
Finally he won, though to be fair most of the alola trainers are weak as f*ck, just look at his past league tobias a legendary trainer with a darkrai.