Never heard anyone use the word coke other than for an actual coke either. Not in real life, movies, etc. Been all around these southern states and never been asked "what kind of coke?". I have been asked what kind of Soda or either do i want pepsi, coke, mtn dew, etc. I have also heard the term pop by a few people who used to live up north.
Are ya'll from the south? Coke is definitely a de facto way to refer to all sodas. In some situations it'd be weird to just say coke but someone might say "hey is there coke at the house" and they just mean soft drinks. Very common in arkansas at least.