They also reflect light from Earth and natural sky glow from the atmosphere, back down. This is why LEO satellites are still readily visible through telescopes or long exposure imaging despite being in the Earth's shadow.

This sub crawls with people who literally have never looked through a telescope in their life saying "ThEy ArE iNvIsIbLe BeCaUsE sHaDoW!". It's simply not true. They are most definitely visible. Not necessarily always naked-eye visible, but they don't have to be for swarms of them to be contributing to light pollution levels.