That'd be really cool and an interesting development, plus reveal.
Vegapunk suggested it wasn't clear who was right and who was wrong in the war between the Twenty Kingdoms and Ancient Kingdom.
It appears to me Lily had regrets over it and Imu, possibly taking her rejection to heart, went on to steal both her body and the Empty Throne, which was meant to remain empty as a symbol of equality between the Twenty Monarchs.
If Joyboy was both the first pirate and belonged to a highly advanced kingdom, then I think, considering Emet's comment to Luffy about making Joyboy king, that it's possible Joyboy was both the first pirate and the founder of the Ancient Kingdom.
I think Joyboy set out to sea, made many allies among races, and with their help dredged up a lot of the technology from the First World, which they then used to create the Ancient Kingdom.
Perhaps Joyboy wanted to be King of the World for selfish reasons, or perhaps others wanted to crown him that because he spread the bounties of the Ancient Kingdom, which ultimately made the Twenty Monarchs feel threatened enough to band together.
I believe the Twenty Monarchs, or one among of their kingdoms, possibly Saint Imu of House of Nerona, managed to induce one of Joyboy's allies into a costly betrayal.
I'm going off tangents here so I'll stop, but I say all this to say I think Elbaph is going to drop megaton lore bombs and plot development, and we're only just getting started.