I don't think anyone ever said that. The statement is that the cloud can't help with real-time rendering. A subtle difference, I know, but an important one.
This demo is yet another example of the cloud not helping with rendering. What this does is add more asteroids to the scene and, allegedly, track them, although I'm not sure what that actually means. I assume it to mean that the trajectory of each asteroid is calculated in the cloud.
This could just as well be snowflakes blowing in accurately simulated wind, or any other particle based weather effect.
The difference is solely in the number of simulated objects, not in the way any one of them would look.