Not just Soviet days. Today, it’s expected (although not mandatory) to attend a course on ballroom dance and etiquette around the age of 16. It’s usually not in school PE classes, but evening lessons in dedicated ballrooms or community centers with professional lecturers.
There are also similar courses for adults commonly available. It’s considered a fun hobby for couples.
While not a reliable source on its own, it can usually point you in the right direction.