Yeah, I think a lot of people make noise in their sleep, just cuz the brain is still doing.. stuff, and it doesn't stop ALL physical action when it sleeps.
It doesn't seem like a stimming thing to me though, since when you're asleep you're not really aware of your body, so it seems less likely you would have the urge to stim..
It also doesn't seem like a Tourette's thing, since isn't that also a kind of an impulse thing? So it seems like it's similar to stimming in some ways, and would also turn off with the rest of your waking actions.
Do you stim in your dreams? XD (I've never thought about it, but now that I do, I don't think I have, personally..)
_________________
"You gotta keep making decisions, even if they're wrong decisions, you know. If you don't make decisions, you're stuffed."
- Joe Simpson