Such a mirror array would at some point reflect enough light at odd angles to be visible with the naked eye.
Moot, the minute you drop some sat into orbit everyone knows it's there even if they don't yet know what it does. Some speculate at least the US uses angled optical/radar shields to hide the bulk of some crafts from ground/orbital view. Sounds like a lot of game for that, especially when aerospace industry spies could provide the same general infos.
I find it more likely that multiple-mirror-telescope tech would be implemented with a swarm of small satellites and extremely precise location tracking and a lot of signal processing later on.
Seems really difficult to fly and calibrate. ie: would certainly need better than gps timing onboard each. Maybe 1km pyramid of four could range each other well enough, no idea. As Jim referenced, membranes and cheap ridgid multi mirror systems may be better. Remember Hubble was scrap when launched, but given a reference image (or in its case, a grind pattern) corrected/adaptive optics fixed it into gold.