I like to think of this like tempering the output space. With a temperature of zero, there is only one possible output and it may be completely wrong. With even a low temperature, you drastically increase the chances that the output space contains a correct answer, through containing multiple responses rather than only one.

I wonder if determinism will be less harmful to diffusion models because they perform multiple iterations over the response rather than having only a single shot at each position that lacks lookahead. I'm looking forward to finding out and have been playing with a diffusion model locally for a few days.