There are some definite signs of over reliance on AI. From emojis in comments, to updates completely unrelated to the task at hand, if you ask "why did you make this change?", you'll typically get no answer.
I don't mind if AI is used as a tool, but the output needs to be vetted.
I think GP may be thinking that emojis in PR comments (plus the other red flags they mentioned) are the result of copy/paste from LLM output, which might imply that the person who does mindless copy/pasting is not adding anything and could be replaced by LLM automation.
The point is that heavy emoji use means AI was likely used to produce a changeset, not that emojis are inherently bad.
What is wrong with emojis in comments? I see no issue with it. Do I do it myself? No. Would I pushback if a young person added emojis to comments? No. I am looking at "the content, not the colour".