True, but I think that could cause issues for astronomers. Instead if seeing small points of light they could see fast moving black spots obscuring stellar objects. In a way looking like eclipses.
They (SpaceX) added Geofencing to the arrays so that they switch off when over radio telescopes. How well that's working now (I notice that article is a couple of years old) is up for debate.
So? Intermittent, short-termed blockages happen (jets and satellites already do this, they just aren't black).
Astronomers don't look first and then aim their cameras, and most interesting features (essentially all of them) require long exposures, which would make this problem a slight, one-time variance in brightness.