Autistic person here. It depends.
I'm honestly kind of disgusted by the whole Sia thing. I haven't watched the movie, but I've seen multiple people (neurotypical and autistic) review it. I don't think that there's anything inherently wrong with a neurotypical person writing a story about neurodivergent people, or even playing one. For example, I think that Eddie Redmayne does a really good job playing Newt Scamander, and he's said that he played him as autistic.
But Sia's movie did Not do that. She did so little research that she didn't even know that Autism Speaks was "controversial" (which is a very, very generous way to put "fucking repulsive piece of shit") organization. I've heard mixed things on if she actually hired an autistic actor for the role; some people say she intended for Music to be played by Maddie Ziegler the whole time and lied about the autistic actress in the first place. But being generous and saying she even existed, the story is that she left the film because the sets and lights and such were so overwhelming.
And then Sia replaced her with a neurotypical actress.
Instead of making the set of her autism movie more comfortable for autistic people to be on.
It's like hiring an actress who's in a wheelchair for a film about disabled people but not doing shit backstage so she can have room to move and then hiring an able-bodied actress instead of adding ramps.
And then when autistic actors basically said "hey, I'll do the film if you want even though this is short-notice", Sia ignored them and when an autistic actor on Twitter pointed this out to her, Sia's response was "maybe you're just not a good actor". Keep it classy, hon.
Sia's movie also promotes "restraint" as a way to help autistic people during a meltdown, which is honestly vile. Restraining an autistic person on the ground like they're fucking resisting arrest and holding them there until they're "calm" is a very harmful maneuver that has killed autistic people, and Sia's movie uses it twice on Music without anyone pointing out this harm. She said that she'd take the scenes out or add a warning about how it's unsafe and shouldn't be done, but she did neither (although I think now she has added a warning, but it's too little too late).
I'm not really someone who's shaken easily, but the "summer days" dance sequence where Sia has Maddie Ziegler do this caricature of autistic people honestly made me feel sick to my stomach. Ziegler herself apparently broke down crying on set and said she felt like she was making fun of autistic people and Sia reassured her that she wasn't, but Sia was wrong again lmao. It didn't feel like representation, it felt like a mockery. (To be clear, I'm not blaming Maddie, I'm blaming Sia for thinking any of this was a good idea).
Also there's blackface in one song, from what I can tell?