I think lots of AI tells these days are leaks from the ai/writer connection into text for the reader. It partly feels like the inevitable result of RLHF with the wrong human's feedback ("I did it! Pick me!") and partly feels like thinking tokens leaking into the main text.

"Here's the argument, in plain terms", "It's not just X, it's Y", "It's worth stating precisely", "The sharper distinction here"... They're things that gesture toward the relationship between the text and the prompt, making it clear where it matched the author's expectations and where it deviated.

Not that humans are immune from coding/writing for their boss instead of their user/reader!