We’ll just have to wait and see, because I have very different expectations for how much longer the arc will go. And last thing I want to do right now is debate on what ifs and take aways.
Understood. I'm just looking at it from how much as yet to even be addressed from a story content point of view:
1. Missing Characters: Tengu, Hiyori, Tama, Onimaru,and Caribou are all conspicuously missing from Onigashima.
2. Plot: There have been hints from Kaido, especially with this "New Onigashima" plan, that much of these conflicts may yet fold back to mainland Wano. What is Onigashima's and Wano's importance to the world and the past? Much more that follows this with individual characters, including Big Mom and Kaido's relationship respectively.
3. Character Plotlines: This is the biggest one. The Calamities are only just starting to be shown off, if slightly. Only 2 Numbers have been shown. 3 of the F6 have been MIA for some time now. The fates of Orochi, Kanjuro and Hawkins are all in limbo right now. The possibility of the BMP coming through along with Pero and Marco's alliance. Along with the fact that who knows what other factors get injected into the arc. Not to mention how Oda even ties all this up together in a conceivable and digestible way (which he will). Kaido and Yamato's flashback is all but guaranteed too.
So yes, still certainly an if, but considering how much Oda still needs to address and not even from an action point of view, I think its going to be a long time before we reach the conclusion of the arc.