I think there's two conflated questions here. I should ideally plan my attack as if my opponent knows my moves, where possible. I should not tell my opponent my moves, where possible. Just because it's not on the news networks doesn't mean the enemy has no way of observing you.

Boxing is kind of a great analogy here, but not in the way you think.

Boxers have this concept called "telegraphing" to call out patterns of movement that indicate what they're about to do. It's one of the easiest ways to lose a fight because an opponent who can read your tells can react to them instead of to the move that they precede.

Even though both participants know that the other is actively attempting to attack them, there's still a significant amount of strategic value in concealing the specifics of imminent activity.

The difference was that they knew exactly where the team would break in. The difference between "there will probably be people trying to enter the room" and "I'll shoot that guy once he breaks the window over there"