This has been a very interesting discussion the last few pages. Some thoughts from me:
1. The comment by Oda by Oda that entering Wano Arc will take at least 1 - 2 years from last year is peculiar indeed. There are some possibilities regarding this.
2. Regarding Wano arc, I think it's best to think of Wano as the arc (I've proposed this several times) where Oda wants to resolve as many New World plotlines as possible. The Strawhats and Minks will play a role, as will the Kid-Apoo-Hawkins alliance (since they were likely defeated by Kaido and then joined him like Apoo or are captured by him as we saw with Kid) with Kid probably playing an emphasized role like Law in Dressrosa. In addition to that we have Marco and the others, if Teach shows up him and the Blackbeard Pirates and if the Blackbeard Pirates show up probably Kuzan will too since he is allied with them. And if Marco, Teach and Luffy are there… Why shouldn't Weevil appear also? Would be convenient.
And we'll learn more about Shanks and the Roger Pirates in the Oden flashback. And of course the whole plot with Kaido and the Shogun and the country itself.
3. So Wano is already filled to the max with characters and plots. I think we can expect it in length to be comparable to the Water 7/Enies Lobby saga. I mean seriously, this is maybe the arc Oda wants to draw the most, it's the highlight of the New World and he probably even underestimated the length of WCI. So given his habits and the fact that he has hyped this arc to no end, the final length of Wano should be considered to be enormous.
4. Which makes the comment all more peculiar, since if Wano is supposed to be that massive - and we can assume given what we know that it will be - wouldn't the author be keen on getting there as soon as possible? No, he himself said it will take some time to get there.
5. Now there are several possibilites: First, he really makes Reverie (which will likely be the venue to give us more on the Elder Stars and of course show us Mariejois) a pretty long arc about 30 chapters. He either breaks with this habits and this will be a Luffy-less arc or he lets Luffy crash it.
6. Or, just a suggestion: If Wano is supposed to be this super-serious, stakes-raised-to-no-end thing, could it be that he shoves a small Strawhat Arc before to give us some breathing space? I remind that Longring Long Island and the Davy Back Fight specifically had that function before the very serious Water7 and it worked (when you re-read it) pretty good. Something like 15-20 chapters. Reverie wouldn't need to be so long then, if we had this additional arc.
6. I and others like Count Mario suggested that Wano could basically be sandwiched between Wano, ending with a clifhanger and then cutting to Wano and after Wano we see the results of it. Given the timeline-to-Wano comment, I think Oda intends to show the most of it before Wano, but he could still wrap it up after Wano in a few chapters.
7. This is relevant given what we can expect to be one outcome of the Reverie and this has been teased pretty obviously: The Shichibukai system will end, maybe under pressure from the kingdoms which were victims of it. And with Kaido falling at the end of Wano, I've always thought it was a good idea to do this simultaneously, so the effect on the One Piece world would be maximum. The Shichibukai system and (with Kaido being defeated) the Yonko system come down together and after then it's complete chaos. So Wano ends with Kaido defeated, cut to the end of Reverie after it, the Shichibukai system comes also down. Would be very dramatic.
8. I have to say that the possibility of Luffy coming to the Reverie sounds very odd to me. First that would be backtracking to the Red Line and with the exception of Sabaody, which was connected with the exception of the time-skip, we have never backtracked. The story has always moved forward on the Grand Line. Some commentors are arguing that an arc without Luffy would be something completely new, but so would be backtracking. Especially if one half of the crew is already in Wano or seems to be on the way. If we now go to the Reverie and we don't get the other side of the crew, Oda basically favours the Swirlyhats. For now this was not the case, since both sides got around 70 - 80 chapters alone on an island (with the exception of protagonist Luffy, who's always there) and I'm pretty sure that was intentional (the time on Dressrosa we spend without the Swirlyhats seems to equal the time on WCI we spend with the Swirlyhats). Either he lets Luffy crash Reverie alone if he does this and the Swirlyhats go to Wano or Oda specifically gives one part of the crew more adventures than the others. And if only Luffy appears at reverie, he would miss at least a certain amount of the Wano arc, since he had to go from the Red Line to Wano. And Luffy has to appear at Wano one point or another. So why complicate this by him going to the Reverie?
9. I would also mention the potential of Vivi. I mean, the departure from her at the end of Alabasta certainly has something (in terms of emotional impact) that many part-time allies lack. She could be the audience's protagonist for the Reverie, especially since we know her character. What if Oda really intends to go to the Reverie without someone of the crew and always had Vivi as the audience's viewpoint (and also someone who is connected to the crew) for this event in mind? Especially, so he can make an arc without Luffy for once. I mean reverie doesn't have to be longer than 15-20 chapters. Thats most of the time enough for Oda to make a place feel alive. And yeah, an arc, even a short one, without Luffy? Sounds strange, but then Reverie is really something special. I would place it, almost on the same stage impact-wise, as when we're going to see Raftel.
10. Luffy crashing the Reverie and taking the spotlight... Wouldn't it make someone like Blackbeard appearing there make less effective? And repetitive? Since we already had such a situation (Impel Down).
I also would add the option of Kaido crashing it. X Drake has captured Caribou, who knows about Shirahoshi being Poseidon. Kaido wants military might to start build up his force. If X Drake knows, Kaido probably knows. Kaido is introduced as a man, who does reckless things no ones dares to do. What if he appears at reverie to capture Shirahoshi (which would raise the stakes atomically)? Would also make for a nice cliffhanger if the Reverie ends on this before Wano, since things Kaido does there, would directly effect the Wano arc.
11. The one year comment could also mean that Oda gave himself some time to effectively wrap up WCI, which will now presumably go longer than 900 and also that he needs some extra chapters where he shows what happens in various locations in the New World in preperation with Wano. Together with a short Reverie (15 - 20 chapters) and a short Strawhat centric breather arc... Could fit. Then again, he only mentioned WCI-reverie-Wano, so no other place was indicated there... :getlost: