well, i dont think we will ever get a correct explaination from anyone, as treyarch probly wants to do with the story like that one company did with ICO and SOTC and leave it open enough so that people create their own idea for the storylines and such.
heck, maybe Treyarch doesnt even know a storyline for it past what we have. maybe those bits and peices are the story, and there is nothing more to it?