Yeah, giant hydrogen balloons really takes the biscuit. As people have already said, the position of satellites is very precise, and balloons get blown by the winds. Especially really big balloons. You’d see the balloons above the satellites, especially big satellites like the ISS. Hydrogen balloons have a limited life. The hydrogen weeps through the membrane (think how quickly a helium party balloon goes flat) so they have a limited life span. Some satellites have been up there for well over 10 years.
Top secret security clearance on a need to know basis is the sort of phrase a 10 year old comes out with.
You can go and watch satellite launches. You can go and see these huge, expensive rockets being launched yourself. Why would anybody put on a ridiculously expensive stage show, then go and dangle their satellite off a balloon.