Oh god how I'll love if the overarching Rocks plotline continues till the end of the series. The biggest thing holding it back is how Oda will portray the typical country liberation part of the arc without Kaido getting defeated. In fact there are many more like-
Oden's claim on how the protagonists of future will defeat him which is kinda lining up neatly now, the question of opening Wano's borders and it would feel awkward if the scabbards' endeavors and struggles were only for Kaido live through this arc lol.
The other side of me thinks how it would be weird if Big Mom would potentially get 3 arcs dedicated to her and Kaido, who I would argue is built up to be the bigger villain in new world perishes in Wano.
His character arc seems to have barely scratched the surface and I'm not even touching upon other aspects like his demonic lineage or him potentially being a dragon.
In my opinion there's an overarching lore surrounding dragons involving the presence of literal dragons in the past, Kaido and Yamato potentially being dragons, celestial "dragons" -their obsession with having them as pets and using their hoof as their symbol. To some extent I would say Monkey D Dragon ironically having that name can be added to that list too. The bottom line is that Oda wants to explore more of this and Kaido could be a central figure in this later
The question also as to why we suddenly get hints about Vegapunk in this arc, and then Kaidou himself almost being
spooked at the idea that the Marines have become stronger, especially concerning their SSG's ( which are implied to be Vegapunk's accomplishment). Perhaps
spooked is too strong a word. But Kaidou is certainly wary. To the point that he agreed to a temporary truce with Big Mom when she offered it. Yet even then, being allied with a Yonkou whose strength and forces rival his own,
it's still not enough. Nope, he wants to find the Ancient Weapons on top of that. It speaks volumes that Kaidou thinks being allied to another Yonkou plus having an Ancient Weapon is necessary to surpass the new age Marines and their SSG's.
Which in my view also means we need to see how and why the new Marine equipped SSG force are viewed as such a threat by a monster like Kaidou in the first place. Implying that the Marines will be playing a role in this arc as well. Doesn't make much sense to see the Marines come in at the end or inbweteen arcs to sweep up the rag-dolled and decapitated remains of Kaidou and the Beast Pirates - when they were viewed as a major reason why they bothered to ally in the first place.