I don't think deception requires the other side to be sentient. You can deceive a speed camera.
And while meriam-webster's definition is "the act of causing someone to accept as true or valid what is false or invalid", which might exclude LLMs, Oxford simply defines deception as "the act of hiding the truth, especially to get an advantage", no requirement that the deceived is sentient
Mayyybe, but since the comment I objected to also used an analogy of lying to a person I felt it suggested some unwanted moral judgement (of a suicidal teenager).
And while meriam-webster's definition is "the act of causing someone to accept as true or valid what is false or invalid", which might exclude LLMs, Oxford simply defines deception as "the act of hiding the truth, especially to get an advantage", no requirement that the deceived is sentient