Author here! This post was human written, LLM proofread, and edited a couple times as folks pointed out broken links and minor errors when it was posted to r/rust a few days ago. As someone mentioned lower in the thread, there's a form of what is sometimes called Bay Area Standard that both very online humans and LLMs have absorbed. I find it FASCINATING that we're in an era where we have to prove our humanity, and the downstream behaviours of things like killing em-dash use in response are interesting to watch in real time. I've made the same mistake, so it's honestly difficult to tell!

I use em dashes a lot and I'm chronically online, so that defense doesn't apply here.

It's things like "perfectly invisible in code review, happy to pass CI a thousand times, then lock your system up at 3am under a request pattern that no one anticipated." which are a dead tell it was written by ChatGPT

I'll bet you 2 beers the LLM you used to proofread the post was indeed ChatGPT.