Clearer would have been: "AI controlled support assistant of Cursor".

True. And maybe they added that to the signature later anyway. But OP in the reddit thread did seem aware it was an AI agent.

OP in Reddit thread posted screenshot and it is not labeled as AI: https://old.reddit.com/r/cursor/comments/1jyy5am/psa_cursor_...

Thanks. They must have added it after, I only tried it just before I pasted my result here.