I think there's some wiggle room with Gallywix's connection to the Brokers, which may lead him to the Ethereals (I'm SURE they know each other) and subsequently the Void. There is a secret Goblin/Inscription only letter on the Cinderbrew venture co final boss's desk which hasn't been read yet on Alpha and I'm sure it will have some more info on this.
It may also be like Aberrus/DOTI where the raid isn't really that relevant to the plot, but the megadungeon is.