Right now it's just hard to imagine how this rooftop battle can be the final confrontation of the Arc, without making the conclusion of the arc feel extremely rushed. Not to mention I see no viable way for the Worst Generation members to win this with there being two Yonko's on the roof. They need to focus all their attention on just one Yonko in order to stand a chance, but they can't do that when they have another Yonko attacking them from a distance. This was made apparent last chapter. Defeating Kaido is damn near impossible while trying to avoid outside attacks from Big Mom, and the same would be the case vice versa.
There is also the sense of the impending doom from the ticking timebomb scenario, or rather lack thereof. I know people are saying it's Onigashima being dropped on the Flower capital, but outside of Big Mom, nobody, anywhere even knows that's the plan. This whole situation just feels like Oda is giving the illusion that this is supposed to be the Final Confrontation, but if you compare it to how that is setup in other arcs, it's very flimsy.
The way I look at it is, if this is truly meant to be the final confrontation, which I am leaning more towards it no being, then yes, this will be Zoro's main fight of the arc. But if it does turn out that Oda is rope-a-doping everyone, and is going to be splitting everyone up again, in order to properly setup his final confrontations, then I just don't see everyone gathering back up to finish off Kaido. Not when there is so many others on the antagonists side who still need to be defeated.
Of course there is the issue of Zoro heavily damaging Kaido in the same vain as Oden that needs to be mimicked, but that can be achieved by opening the scar in this fight. When Oden scarred Kaido, it took days for it to heal. So Zoro doing that now, and going off to fight King later, still means he contributed to Kaido's defeat.