I mean, I fail to see a practical use case for storing the world here. Most practical worlds will be way too big to store them on the blockchain. So I see two possible things to store on the chain:

1. Certain .nbt or .dat or .blueprint or .schematic files which contain unique buildings (for copyright claims or whatever)

2. Specific user data as ingame currency or similar (many servers have their own economy.

About the EULA:

You are allowed to offer completely visual things, so special styles of certain clothing elements, arrows trails, etc (see hypixel) can be easily stored on steem and made available on all servers which use this mod.

I personally thing storing an entire world is just not worth the trouble.
Besides that it totally bloats the steem chain and costs tons of RC to make it work reasonably.