I 100% believe Oda straight fucking lied to Jump when he was starting out.
There's no way this fucker thought this series would last 5 years, he still had all the Shichibukai as original villains. Just that alone would have been at least a decade, and I think that was a lie, too.
What was Oda gonna do, say, "Hi, I know I'm new here, but I want to make a Pirate epic with like over 100 important named characters and too many islands too count."
Fun fact about Oda in his writing and press releases: he's just like Usopp, dude lies all the time. It's kind of fun once you get used to it.