Was it forshadowed ? Most people's reasoning is that will be Big mom downfall arc‚ but why won't she fall in Wano ? That would be her 3rd straight arc ( 2 of them just for her )
Was there any foreshadowing of there being an Elbaf arc ? Even though we know Elbaf since the Alabasta arc‚ it never had that importance as when Wano is first mentioned at Thriller Bark
"Was it foreshadowed?"
Bruh
- Dorry and Broggy told Usopp all about it and Usopp said he wanted to go there
- Oimo and Kaashi said the same thing to Usopp but instead they were going to take him there until he rejoined the crew. They also sailed back to Elbaf post-timeskip in a cover story
- The giant at Sabaody (I forget his name) that they rescued from the slave auction told them that he will see them again at Elbaf
- Big Mom's past. Whether or not she's falling at Wano, Oda hinted at and hid Elbaf's full island appearance for a reason. He doesn't do this unless he intends to show a location later. Same with Lodestar/God Valley. His teases have meaning
- Gigantification/Vegapunk plotlines that have been seeded since Punk Hazard, and are heavily tied together. We got the same connection at WCI, now again at Wano with the Numbers. Smoker and Tashigi have since took the children to Vegapunks lab to reverse the Gigantification process. They've been MIA since even though Fuji hasn't been.
- To add to this, and sort my theory, Bonney and Urogue are the last 2 supernova missing. I've theorized that Bonney's connection to Vegapunk and Urogue's connection to sky islands (and possibly then Elbaf's tree as a means to reach Sky Islands) will connect to make a more concentrated plotline. Aka, I think Vegapunk's secret facility, maybe even Emerald City, is located on Elbaf. Combine those with the Vegapunk/Gigantification plotlines and this might make sense
Tldr: Vegapunk and Elbaf are two heavily alluded to plotlines that need to be addressed before the end. Whether they are one location or not remains to be seen, but they are happening