Having stickers about whether one is open to be approached is a quite different level to having stickers about hugging.

The quote about the hug is an exceedingly typical narrative, in the sense that it's a narrative written in a very typical way. There's no context for her boyfriend's mental state, what he was doing or what kind of day he's had so far. How do I describe how huge an oversight that is?

If a person had a bad day, hugging them to comfort them is a normal social action. If I have a good relationship with a person than I don't have a problem with them touching me regardless of my current emotional state.

Hugging isn't unrelated to the mental state, in a way that involving a grieving person in sex would be. On the other hand it can break a walls that shield the grieving person from his grief. There's more vulnerability.

In general I expect that the resulting reaction of an autists person when hugged gives out information about him being generally uncomfortable with getting hugged.

It might be that I'm badly calibrated because I didn't interact with enough people who I know to be diagnosed with autism, but I wouldn't expect the kind of physical interaction I had with many people at LWCW to happen if those people are autistic.