The idea that Oda will do anything after OP storyline end is total nonsense, the guy have been the most sucefull mangaka of history, and with the piles of money he have, he dont need to do anything anymore.
Ideas like "continue the story in the future", "SH kids", ""New adventures" and other shit are a copium of the fans who can't deal with something ending and the industry use this to make shit like Boruto, hope never happen.
Pehaps he will do some special chapter years after the end, but nothing relevant to the story.
And of course Jump and Toei will try everything to make more money from OP, so could be some kind of spin off manga, movies and even a remake of the anime, like HxH.