Re: One Piece Mega Convo (Spoilers!)
Luffy initially identified Robin as an enemy that time, while Chopper identified as a meal. I don't think Luffy will invite/accept Robin at that time, the reversed condition applied to Chopper. But to think that chapter which specialy assigned with their number position exist for the epic of their Joining/Rejoining time, I don't see any reason why both of them leave Mugiwara. They splitted for a while, but not leaving the group. Robin pledge her loyality after Enies Lobby incident which her epic happened there & it's unlikely for Chopper to leave Luffy as like one happened in Long Ring Island. So my opinion it's too late for now for chapter like that.