So kaido uses a technique called 3 worlds and zoro uses 3 thousand worlds and kaido uses raimei hakke and zoro uses hell hakke.
Coincidence? I don't think so
In that case Zoro/Kaido plot is not end this fast.
As I said in spoiler thread, Zoro going to unlock his CoC with making his adv CoC even stronger, second Kaido not praise him like a strong Samurai similar to Oden,
@Cinera make a great point where Kaido mock every living samurai with "their will be no ever a samurai like Oden" with only mean to get debunked, but he didn´t said anything which put Zoro into that statement. And if Zoro is also really Kaido son, their is no way that theiy not facing each other again.
My assume(Geo also have similar thoughs), Luffy will lose this round, together with Yamato, Onigashima is landing who showing that Luffy,Momo and Yamato couldn´t stop the disaster, I assume then act3 ending with a half victory for Kaido.
However I assume the war still continue, I can see Nami and the others fighting overall in flower capital/Wano and we get a full war scale battle. In case the flyers and calamity get defeated and we learn more about Zoro background story.
Then the final battle with Kaido(who is weakenend) already starts, a epic battle against with all Supernova, while BM and her crew get hold by the navy.