In my world, I have set both commandBlockOutput, and logAdminCommands to False. The problem is the fact that I can still see any player entered commands if I am oped on the server. When the one who fired the commands is in Creative, the output is visible to everyone who is oped regardless of their game mode. If the player is in survival, adventure, or spectator, the command output is not visible.

This has been confirmed on three servers.