I know I'm probably wrong, but I still wanna get this theory out of my head before I'm proven wrong. (Also, I don't know if anyone else has theorized on this, I only started watching campaign 3 less than 2 months ago.)
What if the Luxon beacons are the crystalized essence of Vordo, the Fateshaper(One of gods Predathos ate)? As far as I'm aware, we don't really know how god eating works, but I feel like it can't be the same as eating a sandwich? What if part of it is that the god goes poof? Their essence would be scattered, but what if it crystalized? The crystals, while not as powerful as the god themself, would still be extremely powerful artefacts.
What if the entire story of the Luxon was created through divine interference to prevent knowledge of Predathos from being uncovered? That would explain why the Luxon doesn't respond to their followers. What if they never existed? What if instead of the Luxon being in stasis, the entity that the beacons came from was already dead?
(*Side note for Luxon lovers on how we can still win, even if this were the case: Entities can be reborn. Gods can be reborn. Molly and Kingsley were reborn from the shattered fragments of Lucien's soul. The power of mortals' belief has been shown to be be very strong, via Sarenrae in c1 and Artagan in c2. With the majority of a country's worship, the Luxon could possibly come into being, either as a reborn of Vordo or as an entity of their own.)