@Red Admiral pointed out in a post in this thread that the shadows Kaido sees behind Luffy might all be of characters who could use this advanced CoC in this manner.
If so, Oden would count among those people, so eventually Zoro as well should be able to use it.
Maybe that's what Kaido saying Odens spirit is in Enma was about ? Because he had imbued Enma with his CoC in the past and not just with CoA ?
I think all of these elements could be used to give us the path of growth Zoro's going to take in the following arcs, and if so, he will first need to master the advanced CoC before he manages to surpass Oden.
This could also increase Oden's hype for him to be a legit top tier probably on Rayleigh's ( and Gabans
) level