Earlier quoted context omitted.
that sounds like one of the worst heuristics I've ever heard, worse than "em-dash=ai" (em-dash equals ai to the illiterate class, who don't know what they are talking about on any subject and who also don't use em-dashes, but literate people do use em-dashes and also know what they are talking about. this is called the Dunning-Em-Dash Effect, where "dunning" refers to the payback of intellectual deficit whereas the i…
The em-dash=LLM thing is so crazy. For many years Microsoft Word has AUTOCORRECTED the typing of a single hyphen to the proper syntax for the context -- whether a hyphen, en-dash, or em-dash. I would wager good money that the proliferation of em-dashes we see in LLM-generated text is due to the fact that there are so many correctly used em-dashes in publicly-available text, as auto-corrected by Word...
The HN text area does not insert em-dashes for you and never has. On my phone keyboard it's a very lot deliberate action to add one (symbol mode, long press hyphen, slide my finger over to em-dash).
The entire point is it's contextual - emdashes where no accomodations make them likely.