The One Piece narrative has a lot of moving parts. Many things must be covered, including places, characters, history, and anything Oda feels like adding to make everything more alive. This can sometimes mean adding details to parts of the story where audiences weren't expecting them, including parts of the story that had previously been written. One place in the story that's frequently revisited is Monkey D. Luffy's past before the start of his voyage. It's constantly adding new characters, places, and plot twists to enrich it and make it more relevant to the ongoing events of the story.
Source：https://www.cbr.com/one-piece-luffy-past-changes/
