[1]: I'd even go so far as to extend that "anyone" to: "anyone creating, even with AI assistance!"
It's worse than that. What they are saying is the equivalent to saying that knowing how to do something properly, and having the attention to detail to do so, makes it obvious it was written by AI. It sounds like a prelude to human incompetence, to ensuring that AI products are better than human ones.
About the only semi-convincing argument that I've heard is that AI over uses these tells. But let's face reality here: a lot of people griping about AI generated or AI assisted writing are not looking at over use. Plus a lot of people tend to over use the said tells while they learn how to use them properly.
And it really couldn't have been anything other than the em-dash because I've been deleting the account's comments when they were about a week old so there were no previous comments to draw any conclusions from.
I don't care though, I've been using em-dashes since the late '90s making me partly responsible (along with all the other em-dashers) for LLMs being so fond of them, so I'm not going to stop just because of them.
That said I've only been on Linux for 25 years so I still haven't figured out how to actually get em dashes and have to resort to the double minus like up there.