Bear in mind, to be granted UNESCO World Heritage Status requires the same significance for the human experience as, for instance, the Grand Canyon, Yosemite National Park, The Last Supper, old St. Petersburg, the Great Barrier Reef, the Schoenbrunn Palace, the Great Wall, Angkor Wat, the Forbidden City, Mt. Fuji, or the Galapagos Islands.
The idea that letters home from young flyers about to die have the same significance for mankind as the above is the height of Japan-as-victim thinking. Put 'em in a museum, publish 'em, translate 'em, fine. But world heritage status? Give me a fargin' break.