Oda's holding Zoro back for now but this is what I expect.
- Zoro will defeat Lucci
Proving like Luffy did that they aren't the same anymore. Zoro is now capable of defeating The Strongest Cp0 Agent.
- Zoro will have a big moment with Kuma
These two share one of the most iconic scenes in anime/manga. Not only that, Zoro owes Kuma the biggest debt because of his mercy. Now it's Kuma who needs saving. Whatever that moment is, it'll be epic, heart warming, and iconic.
- Zoro will face Kizaru.
It probably won't be a full fight but remember Zoro's first interaction with Kizaru 2 years back. He needed saving after geting oneshot by him whil he was still injured. How likely would be if Zoro shows up like Rayleigh to stop Kizaru this time around? I know some people believe that will happen. Maybe he stalls and shows off a bit.
- Zoro's Epithet Change
This will be the first time the marines see Zoro in action, None of the marines know Zoro is a Conqueror Haki User so it's time for him to present himself to the world as a serious force. Oda could have Zoro stirring up trouble, running a gauntlet on the buster call Vice Admirals, fodder, who knows.