After reading the story several times over the last two years (After 968 dropped) and seeing how the story has progressed so far. I think I have found the reason why Roger was too early and why Wano will change everything in the story.
1. How did everyone know it was too early?
Throughout the story, multiple characters have made mention of a faithful time where the world would turn upside down. However, all of them knew the time hadn’t come yet.
Let’s have a look at these historical figures.
Shyarly told Roger it would take another 10 years until Poseidon was born. The Sea Kings predicted a total of 15 for Poseidon to come into her power. But that information alone is not enough. An Ancient Weapon is not reason enough for him to declare he’s too early. He did find Laugh Tale, but ultimately, he did not find the One Piece. He hoped that Ace would.
When Oden came back from his voyage with Roger, he was aware of the history of Wano as well as other secrets. Interestingly enough, he advised Toki to jump another 20 years if she wished to see the future she was hoping to see. During the boiling, he declared that the entire world has been waiting 800 years for a figure to appear. Oden predicted that a war would break out in 20 years (Current time in the story).
In Marineford, Whitebeard declared that someone would rise up, shouldering centuries of history and challenge the world. Thus causing a Great War that Sengoku and the World Government would fear.
These three men knew of an impending war. And they also knew when it would happen. But.. How?
I guide your eyes to the Heavens! Beyond our planet. In Space! They knew because they were expecting a specific event to take place. They were waiting for a Solar Eclipse!
2. How does an Eclipse make sense?
You might say “Solar Eclipses” aren’t that rare. And you would be right. They happen around once every 18 months. However, when it comes to Solar Eclipses happening on the same spot? They happen roughly EVERY 400 YEARS.
So now let’s see the events that transpired 400 years ago from the current Timeline.
Noland lands on Jaya, discovers The Lost City Of Shandora and creates a bond with the Shandians and The Great Warrior Kalgara. Ryuma is active on Wano. Slaying a Dragon and becoming the Sword God. The Knock-Up Stream sends the Shandians in the sky.
I believe that Oda didn’t pick that period in time randomly. Kalgara, Shandora, Noland and Ryuma were important figures of their time and we may be missing some information still.
If we go back an additional 400 years, 800 years ago. You guessed it.. It’s Void Century Territory! Whatever happened during the Void Century, I think that at the tail-end of of those 100 years, an Eclipse was involved somehow.
3. What about Wano?
I believe that Wano is the place where the Eclipse is going to take place.
A few months ago, back in July, I was thinking about the inspiration behind the names of all the major pirates in One Piece. However, I couldn’t place Kaido. The closest thing I could think of was, randomly, the island of Hokkaido in Japan.(Because it rhymes. That’s it). Then the SBS for volume 100 came out and Oda did say that Onigashima was indeed based off Hokkaido but was placed differently (not in the North). It was a Kin’Emon moment for me.
The meaning behind Hokkaido
According to Noland’s journal(1122) and the Elder Shandian in Skypiea telling to Wyper that all of this happened 400 years ago, we can “guesstimate” the current timeline to be anywhere between 1510 and 1525. Looking through Eclipses that happen during that time.. I found that this one happened and was visible from Sapporo (which is located on Hokkaido).
Eclipses are events that have a lot of meaning in fiction. Famous examples are: Berserk, Fullmetal Alchemist, Avatar etc… I believe Wano will be the theater of the next Eclipse in One Piece. That Eclipse will play a part in the reason why part of the One Piece and Kaido are located in Wano.
Thank you for reading me if you did. Feel free to comment and let me know what you think. I would love to get some feedback and see how it can be improved.
Theory by LockeyMugi (https://www.reddit.com/user/LockeyMugi)