It's the literary equivalent of thinking someone must be a "hacker" because they have a Bash terminal open.
No, it doesn't. But people are putting that out there, people are getting accused of using AI because they know how to use em dashes properly, and this is dumb.
I dunno, I feel like the base rate fallacy [0] could easily become a factor... Especially if we don't even have an idea what the false-positive or false-negative rates are yet, let alone true prevalence.
I'm pretty sure that all the comments about how it was "rarely seen" are because people weren't paying attention to them before in the way they do now.
In any case, to dismiss something as AI slap based solely on this one thing is both lazy and rude, and should be treated as such.