I’ve encountered people disagreeing with ASD ending with D
But shouldn't it though? According to Webster on disorder:
an abnormal physical or mental condition
And abnormal:
deviating from the normal or average
So something being labeled a "disorder" doesn't mean it's "bad," it just means it's different from average, and in many cases a cause of distress or discomfort. Not all disorders need to be fixed, they can often be treated by simply accepting them and working around any issues it causes.
The problem here has nothing to do with definitions though, it has to do with harassment and intolerance. Whether being LGBTQ+ or on the autism spectrum is a disorder or not is completely irrelevant, what matters is how we treat each other. If you're harassing another person, you're in the wrong, regardless of what the other person is, has, or has done.
Again, let's go back to Webster about "harass":
to create an unpleasant or hostile situation for especially by uninvited and unwelcome verbal or physical conduct
The law (largely irrelevant in SM though, up to a certain point) defines harassment as having real damages and intent to inflict harm. If you say being LGBTQ+ is a mental illness because you know it'll cause harm, then you're guilty of harassment and should be ejected from the platform. If you say it because it's topically relevant and you're not intending to cause harm but it happens, then I argue you aren't guilty of harassment (and you should probably apologize).
The real issue here is intended and actual impact of statements. It doesn't matter if your speech is factual, what matters is the intent and the result of that speech.
I'm not a psychologist, psychiatrist, or any form of therapist, so I'm not going to take a hard stance on whether any given thing is a disorder or not, I'm going to stick to answering my above questions. And in my case, accepting LGBTQ+ and people on the autism spectrum costs me exactly nothing and helps improve outcomes for them. So why shouldn't I do that? What harm could possibly come from me being nice?