I think it is a little creepy, but ethically? You're conducting the same activity in the same way you would have done yourself, but now more conveniently. The recipient still has the same experience either way.
My biggest concern about this is that it could be used at scale for "evil" (e.g. junk calls).
2. This is an automated, unsolicited robocall.
That's literally the reason they have phones.
I'd say that any restaurant or salon that treats a customer booking a table or an appointment as 'unsolicited' might not stay in business for very long.
Robo-booking being used by people who simple put an entry in their own diary - the robot doing the booking and interaction. The human potential client has used minimal resources and because of the ease of use and lack of interaction will not perceive a cost in the making of the booking. I anticipate they'll change, cancel, noshow at a far higher rate than in-person bookers.
Bookings made might then both block other customers and potentially increase the cost to the supplier of administrating the booking [particularly with a micro-business where the supplier end is an actual person].
This, in contrast, is automated deal-making, targeting phone calls at businesses that want to close a deal. The context is entirely different.
Of course malicious behaviour will not comply, but would at least filter the mainstream products.