Yes...the US definitely holds back on the actual operating parameters. Weapon ranges, radar performance and ranges, sonar, top speeds (ie. US Naval Aircraft Carriers can do a LOT more than 32 knots if they have to...even said to be able to outrun most torpedos if they can get oriented to where it is a straight stern chase).In another forum a retired US Navy Captain (Surface Warfare specialist) posted this...
But then, I expect that is also a two-edged sword because I have no doubt that adversaries with capable systems (ie. the Ruskies) do the same thing. Then it comes down to intelligence and what we each REALLY know o each other beyond the "official" specs.