In over 1000 chapters, there is still no evidence that fruits tell their names to their users. In fact, in 800 years, no one has awakened Luffy's fruit, but possibly it has had other users. Despite this, the name has remained a secret for eight whole centuries. Luffy has been using the fruit's powers for years and has met people who knew about the void century, but he has not known about the real name of his fruit until he met Vegapunk.

Lucci's phrase has been misinterpreted based on assumptions that have no basis or logic. As Occam's razor states, the hypothesis that requires the fewest assumptions is usually the correct one.

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.

Luffy we see just walking around is not transformed at all. Anytime luffy is stretching, he’s in the combo form.

We see no change in his appearance besides the stretching when he is in base though which is weird. Which is different than any other zoan we've seen.

Like you said though, it is a minor thing.