I'm in Stockholm as well, no one outside 'expat communities' has attempted to communicate with me using WhatsApp.
Who knows though, maybe I'm not in tune with the general public any more. I know that basically all of my extended family run on iMessage, and some friends use Facebook Messenger as their lowest common denominator.
Sweden. As I mentioned, I may have been extrapolating a bit too liberally based on what I know from Sweden and Norway - I should probably have been a bit more specific.