Keep using them. If someone is deducing from the use of an emdash that it's LLM produced, we've either lost the battle or they're an idiot.
More pointedly, LLMs use emdashes in particular ways. Varying spacing around the em dash and using a double dash (--) could signal human writing.
Show us a way to create a provably, cryptographically integrity-preserving chain from a person's thoughts to those thoughts expressed in a digital medium, and you may just get both the Nobel prize and a trial for crimes against humanity, for the same thing.
In other words, I really hope typographically correct dashes are not already 70% of the way through the hyperstitious slur cascade [1]!
[1] https://www.astralcodexten.com/p/give-up-seventy-percent-of-...
You might as well be sweeping a flood uphill.
Tilting at windmills at least has a chance you might actually damage a windmill enough to do something, even if the original goal was a complete delusion.
0: https://www.prdaily.com/dashes-hyphens-ap-style/ 1: https://www.chicagomanualofstyle.org/qanda/data/faq/topics/H...