If I was in charge of the anime I'd do either of these scenarios:
1) N really gets to Ash. Ash starts seeing how humans treat pokemon as awful, and it becomes N & Ash against all of the pokemon trainers/Elite Four/Champions. Maybe his friends that he made over the series stick with him. Also Max would have a bigger role or at least a cameo. Ash travels around finding the perfect home for all of his pokemon and releases them later.
2) Team Aqua arises again AND THE WORLD BECOMES SEA!
Villager: Does your sciiiiiienceee explain why it rains?
Sokka: YES! YES IT DOOOOOOOES