I’ll die on this hill - no one calls everything Coke and those who claim so haven’t been in the South especially the area around Atlanta. “Coke” is used as an example - for instance, “Hey, can I get you anything? Coke, beer, water, or something?” Yes, they mean they have soda one of which is coke. No one would say, “hey, can you get me a coke” and mean Sprite / etc. At most, they may use it to mean coca-cola products but usually you’ll get a list of which sodas they have and are offering