Probably it will go on sale again.
And I’d like to remind you that, many of those Souls DLCs have some opaque ways to access them, and they are mostly only accessible halfway thru the game. So it might not be a bad decision to play it when the DLC is out, some of us might need to start the game all over again / NG+ just to access the DLC, who knows.
I don’t know if it fits all the prereqs of a FOSS, but there’s mycroft and there’s also jasper
But I have no idea how advanced they are, or how good their 3rd party integrations are.