...it sounds very reasonable, and fits with ideas and facts that we have about Mythworld thus far.
Here's takin' it a step back/foward, depending on where you're standing. Say you're a guy at Bungie (JJ?). You're sitting at your CPU, in some drawing program, but looking at a Warcraft 2 CD on your desk. You're thinking how lame the game gets after a while, and how your new game will be so much better, if you could just think up a new world to place your ideas in.
So you start visualizing a map. Europe comes to mind as a very interesting place (historically as well as geographically), but you don't want it to be exactly the same, so you change some of the landforms, make it look original. You have a map. You start labeling some of the areas, giving them some cool names. And then you start to create races/creatures that occupy certain areas... the drowned kingdom has skrael, rhi'anon trow, the ermine fir'bolg, and so on.
So now you've got a "world", which is starting to unfold inside your computer. A lot of cool races, none of them truly evil in nature. So that's something you need to change, because a good story has a protagonist and an antagonist (or anything to fight). You have this idea, suddenly... a picture of you sitting at the computer, creating an entire world inside a little box, when all of the sudden inside that world comes destruction... something so world-shattering that it will keep a gamer interested, and bring a little balance to this new world you've created inside the computer: the leveler. An idea who's sole purpose is to stir up things in the myth world, so that the "Mythians" have something to do.
Stepping back a second, this reminds me exactly of the myth story and what SD just pointed out. A world, created inside a mind... under one "god's" control, with an antagonist who's sole purpose is to create enough chaos to give a gamer a plotline to follow and a badguy to fight. Eventually through development things would change, more would be added to the story.... but this is where I see "it all beginning".
--Stinger