I doubt it. For example you both just decided to write normal language.

If ChatGPT wrote it, it'd be: [Affirmation], it is not AI who invented it, but humans have been using it all the time before AI, blablabla, em-dash, blablabla. It is not a reliable signal em-dash it is a common rhetorical pattern, blablabla.

I think though it is used by humans, it's not really used the same way. And not in every goddamn post 😅 And then both of you used contractions, you were both able to make a concise point in one paragraph... All things cheap AI doesn't do.