according to wikipedia, nearly all orbits require "station-keeping" which amounts to small amounts of thrust over time to compensate for perturbations due to air-drag, solar wind, the gravitational field of the moon, etc.
so unless these satellites had enough fuel in them to maintain station-keeping processes for such long amounts of time, then I doubt many would survive their parent civilizations
as for detecting them... sounds highly unlikely based on our current technology. Right now we have a moderately difficult time detecting just planets. I'm not sure it would be easy to notice tiny little satellites from so many light-years away