Probably it has something to do with PC (your analysis of the DPRK release). I am pretty sure the original Korean was "gun in", which is "military". However, since a number of these units have both male and female soldiers present, and they do pose in photos with KJI, they seek to broaden the word in English from "servicemen", to "servicepersons". It might be also that they have a NYTimes style book on hand at the KCNA office in Pyongyang. Other than that, perhaps a foreigner is re-writing their stuff...one would expect a liberal socialist to be doing that...accordingly the tone of PC comes about. That's just a guess on my part.
The anti Japanese part is true. There are many ways the Koreans particularly in the north refer to Japan and Japanese in unflattering ways. Japan of course has sins of the past, but you can see that they are a long way from forgiveness, from the communist North least, nearly 60 years out.