Making Zoro fight Kaido was a viable option because there is a way to take him out of the equation. But things are a bit different this time around. I am not saying Zoro can't fight or won't fight Kizaru. I am saying he won't fight him if he's going to be the main arc boss. The main arc boss requires massive hype to maintain tension. It gets reduced when even the second strongest can hold off the most powerful villain in an arc.
Zoro fighting the main arc bosses isn't a new concept. It's been happening from the very beginning:
With Arlong, Zoro was too weak to fight him due to his scar.
Enel was too strong for him.
Lucci crushed both Zoro and Luffy.
Zoro was too weak for Kaido too.
But it's not the case now. Oda can't make Kizaru look like the massive threat that he is if he clashes with Zoro now—unless Zoro decides to hold back and gets crushed of course.
Zoro fighting the main arc bosses isn't a new concept. It's been happening from the very beginning:
With Arlong, Zoro was too weak to fight him due to his scar.
Enel was too strong for him.
Lucci crushed both Zoro and Luffy.
Zoro was too weak for Kaido too.
But it's not the case now. Oda can't make Kizaru look like the massive threat that he is if he clashes with Zoro now—unless Zoro decides to hold back and gets crushed of course.
I see no issue in someone who fought Kaido like him to at least stall kizaru , then kizaru can go and go towards Sentomaru who is injured.
A valid way for him to leave momentarily.