You are grasping at straws
Ryuma cut a dragon, Zoro cut a dragon. That's the ryuma moment. Saying "but it wasn't directly over the capital" or "nobody saw it" is irrelevant. You are acting as if ZKK needs to happen because these specific circumstances weren't met, but they never needed to be met in the first place.
Yes, the ryuma parallels needed to have some pay off. Zoro vs King was the payoff. If you expected more, that's your fault.
Ryuma cut a dragon, Zoro cut a dragon. That's the ryuma moment. Saying "but it wasn't directly over the capital" or "nobody saw it" is irrelevant. You are acting as if ZKK needs to happen because these specific circumstances weren't met, but they never needed to be met in the first place.
Yes, the ryuma parallels needed to have some pay off. Zoro vs King was the payoff. If you expected more, that's your fault.
How is Ryuma viewed in Wano? After his death, he's considered a national treasure; he is the god of the blade, and there's a story about how he slayed a dragon over the capital.
The purpose of Zoro having a "Ryuma moment" is so that the Wano people view him akin to Ryuma.
This is impossible so far.
So, we will get pay off for Zoro becoming a legendary samurai like Ryuma, and he will be acknowledged for it by characters within the story. This is further aided by Zoro saying he will become the King of Hell/Samurai at the end of the King fight, which proves that him leading the samurai as he said in Zou is still on the table.
All in all, if you read Zoro v King and what you got out of it was "Ah, there we go, Zoro got his Ryuma moment" then you've totally misunderstood the purpose of the fight.
We got a tiny lore drop in 1023, nothing has come out of it yet, so we keep waiting.