True, though they are very important for continued and safe commerce in said waters. If you have any kind of ship-based commerce passing through waters, you want good charted data, and you want that data made public for the safety of ships coming and going.
It's worth pointing out that regular, non-military ships do run into uncharted seamounts too. A good example is the discovery of the Muirfield Seamount, which happened when a ship in what charts said was water over 5000 meters deep ran into it. The top was only 16-18 meters below the surface.
Charts. Yes, and arguably that's part of the problem. If everything is just 'charted', you lose sensitivity to the things that are old or low resolution because it's all on the same chart.