Kaido is going down in the hands of Luffy right now on the roof. Something you guys are forgetting is how everything has been hyped to happen during the fire festival and specially the breaking point of chapter 1000. If it were to be an inconsequential battle then the author wouldn't need to try so hard to make it start during this chapter, whith Luffy's speech that he's gonna surpass both Yonkou and become Pirate King...
Nah. This is it boys. It's the time for Zoro to shine and there's no way around it.