That's a really cool idea! I think it would be a lot of fun.

It gave me an idea for a campaign, where in the first session the PCs are all exposed to some kind of exotic energy or radiation that causes them to become "unstuck" from reality. At seemingly random times, they will shift into a parallel universe. Each parallel universe would have a very similar Ninth World, but in each universe the Ninth World came to be in a completely different way (one of them could be the one you just mentioned). Each time the PCs discover how their current Ninth World came to be, they shift to another Ninth World in another universe, and it's a mystery again.