Common sense, perhaps? Large militaries will create their own up-to-date maps for every region of the world where they could possibly expect to be operating.

Common sense, perhaps? Large militaries will create their own up-to-date maps for every region of the world where they could possibly expect to be operating. They will, of course, keep strategic details in such maps secret, but with a bit of marginal effort, the maps deemed to have low military relevance can also be sold to civilians for their business purposes. In order to keep a location secret now, it can't be visible from space. And it can't have surface roads leading to it, or even change the surface significantly from historic aerial photographs of the same location. And it definitely can't have radio signals coming out of it. That basically means tunnels and submarines. There exist people whose jobs are to stare at satellite images all day, classify them, and draw shapes into a database. There is no longer any credible military rationale for restricting by law the creation of surface maps.