My son is autistic and he can't leave our house and tell someone he is autistic without them trying to compare him to Rain Man. He's nothing like the character Dustin Hoffman played, and people are not very nice when they find out most autistic people are not like that.
So your issue isn't that someone is portraying an autistic person, it's that you're worried they're portraying it inaccurately (either in general or relative to the types of ways autism presents in your life) and this will make people misunderstand at least some autistic ppl?
Yes, for example, people on this very thread here have stated that because of the representation of autistic people which is usually white, cis, and male, a lot of women and girls have struggled to get diagnosed as autistic. This has caused real barriers and harm.
Are you disabled? Are disabled people up in arms about this? Who exactly are "people on this thread?"
Amazing how many feel authorized to speak for groups they don't really represent.
And, amazing how often such groups reject this SJW self-proclaimed ownership of their issues.