Sorry, but I don't think that was a Toy Story world. It looks more like an early Traverse Town design to me. The rocket doesn't even resemble the Pizza Planet one (the color schemes are completely different) and the house looks nothing like Andy's house. Plus there's the barn-like structure with an "M's" logo on it, which could easily have been what Merlin's house looked like back then. Basically, there's a lack of anything undeniably Toy Story-related, and considering the other world designs in the design document make it obvious what movies they came from, it leads me to believe that whatever the "Rocket World" is, it wasn't a scrapped Toy Story world. Again, my bets are on either Traverse Town or another world altogether.
Keep in mind that Disney didn't even buy Pixar until 2006 (about four years after Kingdom Hearts 1).
