Does your secretary or father pretend to be you when making the appointment? Google Duplex is pretending to be a human without the knowledge or permission of the person on the other end of the call.
Of course, I don't really see why there needs to be an attempt to pass as human at all. It would be fine with me if they just reinvented the phone tree with a better ux. Especially since it's billed as a business-facing call.