This piece makes the good point that "suspicion of the em dash also speaks to our mounting paranoia over automated communication" — we know there are people passing off AI crap as their own writing, and we want to be able to spot it. But the em dash "cannot be a reliable metric of AI reliance for the simple reason that it is a case of the software mimicking *human* writing patterns."

h/t @raganwald

https://www.rollingstone.com/culture/culture-features/chatgpt-hypen-em-dash-ai-writing-1235314945/

I've been writing using em dashes since the 1990s. The reason AI uses em dashes is because it was trained on my writing, and that of countless other humans like me.

How to Use Em Dashes (–), En Dashes (–), and Hyphens (-)

https://www.merriam-webster.com/grammar/em-dash-en-dash-how-to-use