My initial reaction was one of surprise that Harry would even attempt to bring up ELIZA in a conversation with a non-muggleborn NPC. Even Hermione would probably take a second to access the relevant data item. He seems to be better at judging his audience than this.

If he wants to convey the chatterbot idea, he could use a relevant local example, like some talking magical item, or some magical creature known for mindlessly parroting human speech. Maybe Binn's ghost, or something.