One missing information about all other objects after the 1st balloon is their nature and speed. Why should they keep this information classified? It's like the objects were a lot more complex than a balloon (propelled drones?), with varying attitude and speed and telling what they were doing when they were detected would reveal what they were doing while still undetected, that is, giving information on military capabilities to the Chinese. Pure speculation on my part of course, still I'm puzzled by all this secrecy.