It is learned. As an example, I present myself, who would have had NO idea the older lady was insinuating that she'd also like a beverage.
I think the instances (older lady vs. your SOs) are similar but separate. The former is a manner of politeness that's gone out of fashion -- not wanting to embarrass your host/family by calling attention to their etiquette failures. It's a very "Emily Post" tactic: getting what you want (a cold drink) while allowing all parties to save face.
The stereotypical communication gap between men and women is a whole different beast, and not one I'm about to rodeo.