Givin Ash, Ubers and Top Tier fully evolved Pokémon with almost no emotional background as always, belongs to the plan, of allowing Ash to destroy Leon and everybody else, like ridicuously destroying (LOL i know) in a way that will admit Ash as the main protagonist once again. Think about it, if Ash wins the league having developed bonds, friendships, love, overcoming obstacles, featurint a kalos artstyle, it would be hard then to continue because it would really feel like the dreamed moment for Ash since 20 years ago. But if they do it having Leon like "lol Ash fag your team full of Ubers" "yep and yours too fag, aiight Moltres, use Heatwave" "go Dragonite use giga Outrage against giga Charizard's remotecontrol wings!", while all of us eat popcorn, we will be ready for new seasons featuring Ash finding himself once again as the underdog.
Pd:Can't wait too see Dragapult being murdered by gengar, just wish gengar still had levitation but Broooo