What I'm left to wonder about, now that the cosmology of FFXIV has gone down such a completely different direction, is who or what exactly are the Twelve?

They aren't primals or eikons, and are apparently gods of a far greater magnitude of power, so much so that it would be absolutely life-threatening to summon even a mere fragment of them.

And, yet, throughout this time, the Twelve have been silent. Do they even exist, the way Hydaelyn or Zodiark do? Or are they just figments of prayers and faith, like any ordinary primal, except a lot stronger?

(Or, here's my very, very wild and totally unsupported hypothesis: Could the Twelve perhaps be the incarnations of the surviving 12 shards of the Source? Hmmm....)