So far no teacher has behaved like that in terms of DD, but that is because she does not have a 504/IEP and they don't know anything about it, other than what I've told them.
The teacher last year seemed to think I was just making it up, because DD acted so "normal" in her class.
But I have worked in a school with teachers and they gossip and gripe about kids and families in the lounge. There are some teachers who are very good and love all kids. But I would not say the average teacher is free of biases about disabilities, or that they "embrace" kids with challenges.