Without that, you have a much bigger solution space to search for the optimal approach. And you likely wouldn't even want that optional solution anyways: if your humanoid robots have sufficiently strong actors, optional solution for, to pick a simple example, navigating a staircase would likely be vertically scaling up the handrails through the slot in the middle. That might save staircase capacity and a tiny amount of battery (better aerodynamics!) but it would certainly ruin any humanoid qualities.
On the other hand, if you take another step back and think of the query input to the diffusion model, perhaps a text "human walking up to a higher floor" in our stair-climbing example, then you are absolutely right, that would be much closer to what we'd call "conscious" than I had ever imagined!
(my usual model of technical consciousness is an entirely different beast, the "simulate before act" approach with the additional requirement that the simulation includes a "self" and "peers" and the simulation includes rules/mechanisms that put them in the same category)
robotics also needs instant reaction time, which i don't think this kind of thing is good at
maybe something like a rough pre-simulation step for further rapid prototyping work? can't imagine the practical application..
disclaimer: i have no idea what i'm talking about, and am just going through the motions, much like the diffusion model under discussion