I have always enjoyed good punctuation. And being a bit of a nerd myself, I used em dashes throughout University in my essays. To me it felt like a cool little keyboard shortcut that only few knew about. I still use them today—in emails and reports. I haven't yet been personally called out for using AI, but I have noticed a lot more people using them.
So what if people use AI to help them with their grammar and punctuation. At the end of the day, people are still sending messages they endorse—even if it's not one they could have articulated without some help from AI.