That appears to be the case, yes. Tense border, but very quiet right now. Hordes of North Koreans in Chinese border towns being ordered to return back to North Korea. Many going with flowers and then across the bridge from Dandong, China to the other side. Pyongyang run restaurants closed down for a number of days, in mourning.
I like your tagline, he may have been assassinated.
After his stroke 2 years ago, he has been weakening and this was no surprise.
The Kim family is firmly in charge of NK anyway they want it done.