Absolutely agree. NT librarians are also more likely to only know about well-reviewed and bestseller autistic authors like Grandin and Robison, and autism parent books, and think that's good representation.
It's not that they can't do the research, it's that the librarians doing the selection work are frequently overworked, and have limited time and a lot of pressure to make every penny count. The lowest hanging fruit is usually the mainstream stuff.
Requesting a few specific title/authors and linking to reviews can really help. Introducing resources like ASAN so they know why these voices are so important is also a plus.
Then spread the word that the books are available locally. If they don't check out, the odds of them getting more goes down because shelf space is finite.
This message is brought to you by a long time library worker who wants to see more #ActuallyAutistic authors on the shelves! ;)
BZBrainz