Does the allignment of something that doesn't have free will matter?
well, you RP it as if good has triumphed over evil. For what better humiliation for an evil being is there than to serve under the goodly command of a Deliarite? besides, Deliar has a domain of trickery ( i think, might not be right, but anyways,) and he could have tricked the shadows into servitude.
besides, Deliar has a domain of trickery
No he certainly does not. The "tricky" halfling god is Branderback who governs stealth, night and darkness. So his shadow summons are very spot on.