Interesting. If you can find that newspaper article, I'd love to read the details.The kwans were subsequent to the end of a 35ish year annexation. 1910 to 1945. Three and a half decades.
Every public dojang of KMA was shuttered, and a snitch network was established. Dojangs that weren't burned down were turned into JMA dojos.
Much of this from first hand KMA artists who were there and tild me directly and from individuals whoses parents were 1st hand witnesses who carried the events forward.
I have a korean newpaper article, (somwehere around my office) on one korean dojoang where the records of the school were kept intact through both transitions and name the Japanese sensei who ran the school during the 35 year period.
The fact that dojangs were occupied and converted is common knowledge within many KMAs and can easily be verified.
Have you confirmed that the dojos in question were teaching Karate and not some other JMA such as Judo or Kendo? After all, Karate didn't come to Japan until the 1920s, so I wouldn't expect that Japanse instructors would be teaching Karate in Korea prior to that. Is it also confirmed that these instructors were teaching Koreans and not just other Japanese?
If this is correct, it raises questions. I believe there is solid documentation that the founders of the kwans originally trained outside Korea (in Japan mostly). If Koreans were learning karate from Japanese instructors in Korea for 35 years before the founding of the Kwons, then what became of all those students? Did they join the kwans? Did those lineages die out?
Any KMA experts want to chime in?