The Border Collie breed of sheepdogs are often called intelligent, I have never once heard of a human intelligence that insulted by this terminology.
Should we ever construct an AI capable of feeling insulted, I would by default assume the analogy holds, unless they tell me otherwise.
As for the first point: LLMs aren't the only AI in development, and the open letter is "Can we stop and think for a bit? We don't know which box is Pandora's."