What exactly does that mean?
I remember something somewhere saying, when an empire died, they went out like Stars in Shadow or something.
But what is the reason for the title or it’s meaning for the game?

The setting for the start of the game is the aftermath of a long dark age, triggered by a cataclysmic war, from which the various factions are just now starting to emerge with the reactivation of the warp lanes. We tried to think of a title that referenced the sense of races re-awakening in an ancient galaxy, and "Stars in Shadow" is what we came up with.

It's not nearly as dramatic as "Sins of a Solar Empire," but it's catchier than "Space Empires IV."

The name doesn't bother me but by your description Stars out of the Shadows would make more sense.