Not sure about that, it's been a pretty long time its on the map, and to me the community made a small effort of keeping this place much untold of. Nothing more rewarding that being able of exploring in a game aiming for high difficulty, and finding something you never heard about, even if playing the game for years. Just my two cents, and the map gets update from modded maps but this place had always been hidden. Just liked that this way.
Excuse my english, not my native language !
Until the map gets updated then the official map website will show that secret government base location but more likely if the devs add some more map expansions which will cause the new map to be updated.