@EvoWarrior5:
I actually feel the opposite way, I do think Kaidou will be down before the Reverie happens. We only just saw Vivi & co set sail. Even with a Marine escort and going directly there, that's still sailing over a quarter of the world we're talking about. Due to the instability of the Grand Line, it seems logical that everyone who has to cross it will leave way in advance to account for delays. I'd expect most of the kings and queens to arrive a comfortable several days before the actual thing starts. So there's the long sailing plus the early arrivals most should have.
It's true that the Grand Line is unpredictable but as far as times go…it's always been a bit flexible in One Piece hasn't it?
@EvoWarrior5:
It will also still be a while before Kaidou goes down, but I don't really think it will take much longer than the expected time of the Reverie. Also, just thinking story-wise, it'd seem good to make the downfall of a Yonkou one of the (sudden and unexpected) main points at such a crucial event to OP world building. After the downfall of the first Yonkou there will really be a "where do we go from here?" moment, and the Reverie seems like a good opportunity to really make that felt.
I dunno, I feel like the Reverie will be centred around the whole Shichibukai issue, with Doffy's downfall and Fuji's goal to abolish the system taking centre stage.
I think we might get the waters muddied a bit with some news of an incident that's taken place at Big Mom's tea party but overall the focus will still be on the Shichibukai.
Kaido's downfall would overshadow all of that and would kind of ruin the build up we've had for the issues we expect to be dissected at the Reverie.
So I don't think Oda will pull the trigger on it by that point.
–- Update From New Post Merge ---
@Roronoa:
I also wonder if Neko runs into Weeble if he looks for Marco.
I'm hoping this is the case, and Weevil ends up tailing Neko and Marco to Luffy, bringing him into the main story.
@Roronoa:
About Vivi sailing to MJ, I have another question: Can there be a eternal pose to MJ? After all it is the redline. FI has a magnetic field the log pose can lock on to, but the redline? Maybe the gorousei give VivreCards to their affiliated kings.
I imagine there's some distinct system in place, yeah, but like you've shown we can't be sure what it is.