I think you're drastically misunderstanding how this proposed constellation would work. It's not putting 50,000 "moons" in the sky. You can only see the light from the mirror in that one specific 5km patch of land that it's being aimed at. The vast majority of the world - including all the "wilderness", because who would pay to point these things at random patches of undeveloped wilderness - will not receive extra light from these things.

It's more like setting up floodlights at a construction site, or street lights in a city.