This panel literally contradicted your entire argument. Notice how he says "we won't last to actually fight Kaido", not himself. That shows that he is including Luffy in the battle, which goes back to my initial point that Zoro saying he wants to slice up Kaido is to foreshadow the fact he'd wound him like Oden did, but will not actually be the one to beat him, since it'd be Luffy
All Zoro said is he wants to slice to Kaido because he is rumored as the strongest. But slicing up Kaido and beating him are two things different. Zoro will accomplish his wish(slicing up Kaido), which will be used as a parallel to Oden's scar, but the one who'd beat him is Luffy
Also
> Zoro training with Momonosuke isn't even comparable to Luffy taking Momonosuke's mantle to beat up Kaido for him
> Zoro's connection with Tama is nothing compared to Luffy's connection with her. Luffy is the one who made the promise to Tama to liberate Wano by accomplishing Ace's will, he is the one Tama views as the older brother like she did with Ace
With that said, i never said Zoro had no connections to Kaido this arc. Infact, i could show you an old post of mine where i said, Zoro's development in the arc was comparable to Luffy's(especially with his connection with Hiyori and Yasu), but as far as Kaido is concerned, it's nothing comparable. Infact before Zoro's statement about slicing Kaido in latest chapter, his intentions weren't that clear, especially when before the raid, he was aiming for Orochi instead. In Luffy's case on the other hand, it's something Oda took his time to build up since Luffy defeated Doflamingo in dressrosa, to the point he actually stated he was thinking of ways for Luffy to beat Kaido even before the events of WCI
And as stated above, Zoro includes Luffy in the equation of the fight against Kaido because he knows Kaido is Luffy's opponent, will do everything in his power to help to defeat Kaido, with his contribution being either reopening Kaido's scar or creating a new one(hence his claim of wanting to slice Kaido), but will ultimately leave the task of beating Kaido to Luffy because he respects his captain and his dream.