It's possible but I disagree. It has all the elements of a retcon to me. Gear 5 was maybe always planned but the way we learn about Nika and the way we learn about the real fruits importance and power seems too sudden to me. I mean, we get the info from a completely random character, Who's Who, whose only purpose is to retcon that aspect of the story. There is a lot of foreshadowing overall of course, and certainly Oda uses things he's already written to perpetuate the story further (not the same as foreshadowing). But the whole "government hid the real name of the fruit" thing literally came out of nowhere. Even originally when Luffy ate the fruit, I think it's Lucky Roo who refers to is as something they stole "from an enemy ship," not the government. I'm not trying to shit on it or anything lol, I absolutely love One Piece. But people definitely exaggerate how much was planned. A good story changes and evolves over time, and it seems clear to me at least that this is a change Oda made well into the journey and not something he had in mind from the start.