Actually, NK was one of the first countries to take drastic preventive actions against COVID, so even of they do have it and they’re not admitting it, it’s still likely that they’re doing ok.
But North Korea is so secretive about things like this that it wouldn't surprise me if 10,000 people have it but we don't have any reports. Also, North Korea is known for locking people up for certain reasons, so that could have been what they did