I had not considered this but you may be right.
Savathûn apparently doesn’t die in TWQ so we have to assume that whatever happens to her will be in Lightfall.
We don't know what Savathun's game is. Other than to be rid of her worm.
Once she's done that we don't know if she'll fight alongside our Conspiracy of Light....or turn back around and fight alongside the other minions of the Darkness.
We know she is in it for herself. She doesn’t just want to be free of her worm but free from the darkness and the light.
I think she will help us as long as it benefits her and turn on us when it doesn’t.
I don’t think we can just allow her and her lucent brood to go unchecked so I don’t see a peaceful outcome.
Willing to proven wrong though.