This wouldn't be a proper fallout adventure without vaults, it's as simple as that. 

I wouldn't be the one doing the world building if I didn't know what needed to be known. Almost everything in the information post is made up; I don't see why vaults would ever need to be an exception.

Plus, it's not like this hasn't happened before, there's another wiki somewhere that was created specifically for Fallout roleplaying and they have a Vault 199. Fortunately, we aren't going off of that.