I mean you would stop using the OK Hands thing when trying to communicate with a group that has for (possibly arbitrary) reasons decided that that symbol is bad

I mean you would stop using the OK Hands thing when trying to communicate with a group that has for (possibly arbitrary) reasons decided that that symbol is bad, and thus anything you say is bad, right? At least temporarily until you got synced up with that group? There is a place for the strategy of just continuing to use something and push through the noise there, but the em dash is not in that place. Common perception of it has too much momentum you cannot overcome like that, which - at the time of writing - makes it a bad choice. How it will look like in 12 months we shall see, but today, I would advise against using it (without acknowledgement) in texts that talk about AI.