No. If someone asks you for a coke, you give them a coke!
Even as someone who has ordered a soda as a "Coke", I agree it is a fair assumption to just bring the person a damned Coke.
That said, I'm usually pretty happy with the result either way.
(Until the Dave and Busters waiter mixes Coke and Sprite [50-50] in response to my request for Ginger Ale, of which, they apparently had none.)