Did not know that , from interviews i read it seem like he did way less .
Thanks for the info .
He might have done less than Strong World, but his contribution is still very significant. If you can find scans of One Piece Vol1000 (it was a promo book sold or given out when it opened in Japan I think), you'll see that Oda's touch is all over the movie. I really recommend it, because you can see that while he designed all the costumes in the movie, other Toei designers did the Z Filler Arc costumes, so he definitely didn't care as much for that (looool).
But the most striking thing to me is the collection of drawings he did showing the entire life of Z from a young boy all the way to the end of the film. All the montages in the movie showing his life are all directly based on the illustrations Oda did detailing the character's life. That's a really significant creative contribution to the foundation of the movie's story as well.
For Strong World, I think Oda definitely did much, much more "work" in terms of designs though. He didn't just design all the costumes, but also ALL the monsters in the movie, and he did tons of landscape layouts for the various locations throughout the movie, etc. Soooo much artwork. I think handling the story outline, costumes, designing the opening movie, and drawing Z's life was definitely less work in comparison.
I'd suspect that he only makes them because he wants to. He's already richer then the dreams of avarice at this point, so I don't think he really needs the money, and I wouldn't think Shueisha would try and force him since they wouldn't want to do anything to annoy him at this point either.
That said, he may force himself so as not to disappoint fans, but I rather hope not.
Yeah, I agree that he's doing it because he wants to, but I think the motivating factor is also in how much more popular the movies are now after he personally took over as an executive producer. By making the movies into big blockbuster movie-only events within the same One Piece world, his personal touch has really elevated what fans think of the One Piece movies. This alone should be a huge factor, even before looking at the tons of money he's probably also making from it.