Again, this fundamentally has nothing to do with ZKK.
It has to do with people choosing ZKK over Zoro being relevant for the next 20-30 chapters lol
If Oda decides to give Zoro a commander fight, then also deliver this fan notion of an execution on Kaido, be my guest lol. I'd enjoy that shit.
But lets make that crystal clear, it IS a fan notion.
Killing Kaido has never been set up by the story.
Cutting Kaido was. The former is backed by assumed parallels and fan feats. The latter actually had dialogue in the story to achieve it.