Going into Whole Cake it does sort of feel like every Strawhat has a prerequisite in their contracts stating they get an arc about when they try and leave the crew, preferably for a noble cause or act of self sacrifice.
When they finally get around to it, the arc where Zoro leaves the crew is going to be by far the shortest arc ever.
Zoro: I'm leaving the crew.
Nami, Usopp, Chopper, Franky, Brook: WHAT!?
Sanji: Finally.
Luffy: *Enters A State Of Shock-Despair*
Zoro: -to get some more sake. I'll be back in time to take the watch.
Nami, Usopp, Chopper, Franky, Brook: *Collective sigh of relief*
Sanji: Goddamnit, marimo. Don't play with a guy's emotions like that.
Robin: *Robin Giggle™*
Zoro: Whatever. See you losers later. *Leaves*
Luffy: *From his State Of Shock-Despair* Where'd all the meat go? Sanji, why are we out of meat so fast!!!
Haha. See, the joke is that Zoro would never leave the crew or Luffy's side unless it were an order or he was just going to find something real quick like...
...
...!?
Wait. Oh god. No.
When they finally get around to it, the arc where Zoro leaves the crew is going to be by far the shortest longest arc ever.
I mean, how could they be so reckless as to allow that boy venture ashore on his own? We'll be lucky if we ever see him again!