I mean, you could kinda see it coming that Ash's journey was coming to an end when he became the champion.
I hope the next series takes place a bit in the future and we get to have Ash making at least one cameo as the champion, clearly older but much more expirienced and still with Pikachu at his side.
That would be much better than Yu Gi Oh GX where all we see of Yugi was a quick cameo at the start IIRC.

oh boy , I remember this episode.