Zoro doesn't have to do something in relation to Kaido. All that would accomplish is him undermining Luffy's victomy and in a sheap way nonetheless. What's better for him is to do something against the incoming marines/WG ships when everyone is down/incapable of fighting mirroring the legend of Ryuma procting Wano. That would be a cool moment for him similar to the nothing happened back in TG and it ties well with his Wano backstrory. And the best part, it won't undermine the MC of the series which let's not kid ourselves is the agenda of most ZKK fans.