This is quite simple.
Why all the Zoro haters were saying that he won't fight Kaido, he won't even meet him etc. etc.
Because participating in the fight against Kaido is an hell of a portrayal and they didn't want Zoro to gain such portrayal, this is undeniable.
So they've already confirmed which portrayal is better, even though they did it only implicitly. Now it's only backtracking