Well if you look around you many of us Zoro fans desired that things could be different. This is not exactly a given that they won't be different although it looks intrinsically quite unlikely.
We know that Luffy likely spelled "I got this" since in the first place the Grandmaster was unable to keep fighting. What would it happen had he returned remotely healthy? Would Luffy allow him to help? Would Zoro wish it?
Well, let's say probably not. Luffy would need to fail pretty bad for Zoro to eventually save his life at that stage. So again, it's a visibly less likely situation given the implications we are lately crossing to.
And Luffy was stupid against Kaido first time and was begged.
Second time in base he managed to dodge partially Thunder Baga and kept fighting. And Luffy COO didn’t improve from first fight to rooftop.
So Luffy being insta begged by Kaido is not straight power level.
Pushing Kaido to Low diff and beating Queen extreme diff are around the same level.
Gaban beat Oden who has COC. I don't see how he did that if he didn't have it. Could be unconfirmed like Garp is when we know for sure he has it. Bullet is like Shiki case where movie is non-canon on events, but not the characters.
CoC is not everything in a fight, I thought this was crystal clear.
Luffy himself was a CoC user on Marineford yet still standing as a fodder. However we don't have proof that there's a non CoC user around who can beat Current Luffy, although such scenario looks seemingly probable.
Goalpost shifitng what ZKK means is lame, every non ZKKer was saying the only way Zoro would kill Zoro would be through execution, ZKKers didn't find this acceptable before 1010. You are now a ZEKer (Zoro executes Kaido).
But Zoro isn't killing or executing anyone, because Luffy would kill if he wanted to kill, because Kaido doesn't deserve a glorious death, because Yamato is still his daughter, because Zoro is a hero to Japanese children.
This is an arc 400 chapters in the making for Luffy to show to the world he is the top pirate king contender - having Big News morgan headline "Kaido defeated by Luffy", only to have page 6 news be "Zoro kills Kaido" is Stupid and Zoro isn't outshining Luffy on the world stage for this victory.