Yes but it can be done on a much smaller scale.

The smallest exoplanet discovered is Kepler 37b it’s smaller than mercury.

And planetary transitions are hard to detect because they are very time sensitive if you put something in a solar synchronous orbit between two planetary system a thin polarizing sheet which can be as thin as a solar sail can easily serve as communication device.

Any civilization needing one would easily be able to drag an asteroid which should have enough raw material to build a polarizer a few 1000’s of KM in size.