Yeah. People tend to assign vice-captain to Zoro, but I don't think that's ever been mentioned in official materials that just label his position as more of just a fighter.
It's a title other characters have recognized him as, so even if that's not his role in the crew, that's how the world outside the crew view him as.
EDIT: Case in point
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–- Update From New Post Merge ---
I think we will get more crew moments after Wano.
- My bet for next arc is that Luffy will go back to the Red Line for personal reasons.
- I don't think Law will be present for most of next saga. He will agree to meet Luffy again later in the story.
- Just after Wano, the crew will have a few chapters by themselves. At most, Caribou will be there.
- I feel Luffy learning advanced haki already put him far above the others and close to become Pirate King, so next upgrades will be for the crew.
- If next arc is Mary Geoise like I expect, then it's the perfect chance to feature Robin and Jinbe, like Zoro and Sanji are having their turns (I feel Sanji will still get a huge moment in Wano, as it will close most of WCI's plotlines once the BM Pirates return).
- Vegapunk arc has a lot of potential for Chopper and Franky to learn new science.
- Elbaf is for Usopp and, I guess, the 11th.
- I don't know about Brook, but Nami will certainly getting the spotlight on the way to Laugh Tale.
There's a lot of places the story can go after this arc. There's a lot of things going on in the world that Oda hasn't made completely clear what is transpiring. This very battle with the Beast Pirates is going to end up changing the power dynamic and structure of the world, especially considering the abolishment of the Warlord system already ended up doing that. I also don't believe Big Mom is going down this arc. Luffy has already stated he has reserved her for later after he beats Kaido, so she is going to be a persistent threat. Moreover, after this arc, we will only need 1 more Road Poneglyph and its anyone's guess where it actually is.
Honestly, any prediction where the story goes by this point is valid.