It's only his hype because of which people think that he could use it consciously. Other than that nothing proves it. No direct implication or anything
Besides Asura's statement, we never saw Oden use COC burst either.
Maybe not at his limit but he was still pretty desperate to save his country. I don't personally think not being at his limit is a counter-point but it's your opinion so okay.
Oden's statement meant he was already in his prime (even the narrator supports this by saying that Oden cane back invincible) which means there's nothing else he could do to get stronger.
So going from saying that to unlocking a new ability is contradictory.
This is inapposite to Zoro's situation where he is not in his prime and was only talking about his current fighting ability
But I'm not talking about that lightning, I'm talking about the one which comes off from the weapon (Or in Luffy's case, the hand) itself. It's pretty different from CoA lightning and the lightening the forms as an effect of the CoC clash. The latter 2 are pretty confusing, yes.
We even have situations where COC attacks touch and where they don't touch, we don't even know what that means.
When Zoro unconsciously used his, we see a black stripe coming from Kaido, we don't know what that means either