There’s an old statistical observation, a country with (if I remember correctly) >50 telephones per 1000 inhabitants can no longer function as a totalitarian or dictatorial state. It’s a tipping point, and whether a government can technically take out telephone exchanges appears to not be an issue. Generally they need the infrastructure to work for them too in complex ways that makes it impossible to take it all out or control access. It’s been observed in Eastern Europe over two decades ago.
If you look at the numbers presented in the article, North Korea is just below the tipping point for fixed lines, with mobiles growing very fast. I’m guessing things are indeed about to change there, on a scope well beyond a “digital revolution”. The leadership can start packing their bags: out within a few years, possibly much sooner.