I've been thinking a lot about Zoro's role when he's dealing with the grim reaper and now that Kaido is most likely done, it's difficult imagining a ZKK scenario until further notice. However, this thought is not farfetched what Zoro might still pull out:
Even if ZKK doesn't happen (if Kaido's now done for good), I think Zoro still has the potential to live out one of Ryuma's legacy's: Fighting off the World Government out of Wano by himself. It is not a coincidence that the one CP0 guy immediately flew away from the island; he'll most likely give the reports of the war conclusion and they will all start their invasion soon. Luffy is done, other characters are heavily weakened too but Oda specifically highlighted the fact of Zoro possibly overcoming death despite the battle situation. Unless Oda just likes to waste panels - well, it is nothing new now... - I fail to see adding these grim reaper moments without a valid reason.
Therefore, we might see a potential new PU soon or even Zoro making Enma black, forging his own "Shusui". This will be the moment in which Zoro will shine again, having his next Thriller Bark moment.
We don't exactly know the full force of the CP0 and whether they have some hidden heavy hitters left but invading Wano, only to realise that they are still incapable taking it due to one individual ronin battling them off. This will also be a moment of Zoro making himself more famous than ever.
Sure, he took down King but nobody saw it exactly. He gave himself a new epithet but no person really witnessed this one either.
However, people will start looking at the man, calling himself "King of Hell", protecting their country by fighting off the very large world government trying to take their own home by force.
I don't know what you all think about this short theory but go ahead to share your viewpoints towards it!