Personally, I have a feeling Elbaf will end up being a shorter arc than some people expect. Or at the very least, the Elbaf arc will end up being the start of the Final War. I mean, where better than a Norse inspired island to start Ragnarok?
Oda's Jump Festa 2024 message did say that he did consider skipping Elbaf and just jumping straight to the next part of the story. I think he's just doing Elbaf because he knows the fans will be disappointed if we skip one of the most hyped up islands in the story. So, I think he'll probably keep it shorter, 20 to 30 chapters ish. Zou sized ish.
It kind of works with his pattern. Any story arc heavily featuring huge characters like Zunesha or the Giants are relatively short arcs, just for the contrast. Like some sort of weird joke.
I just think Oda probably wants to keep this story moving. So, we're probably not going to have a whole separate adventure on the Giant Island now that we've attracted the attention of the Gorosei. The Gorosei (and maybe Imu) are likely going to start following the Strawhats around, wherever they go, trying to hunt them down. They probably won't be able to stay in one place long, unless they want to put the people of that island in danger.
I mean, I guess Oda could split the difference and just have the Final War take place ON Elbaf? That might be more satisfying than anything, I guess. I don't know if we should count on that, because it feels like the Final War probably needs to take place on a bunch of different islands. But, that could work.