doctorbadwolf
Heretic of The Seventh Circle
I’m primarily going off of Bakers articles and twitter and forum conversations with him, so it’s entirely possible that my interpretation is non-canonical.As far as I'm aware, the majority of the Seekers believe in the Soverign host, they just reject them as unfit for worship. The Sovereigns created and condemn mortals to Dolurrh, where (the seekers believe) they simply dissipate. Many seekers may believe that the gods do this out of fear or similar, to prevent mortals achieving the divinity that they hold the potential for.
There likely are seekers who believe that the sovereign host simply doesn't exist, but as far as I'm aware, its not most of them.
The Voice of the Flame, whose sacrifice allowed mortals to interact with and be empowered by the Flame was a Paladin of the Sovereign Host. I would imagine that while most followers of the Silver Flame would view the Sovereign Host as too distant and disconnected, they don't refute their existence.
The elven faiths are almost exclusively build around the concept of avoiding the dissipation of the souls of their revered ancestors in dolurrh. They seek to avoid the fate that the gods inflict on the dead, either by keeping them in this plane as undead of a sort, or by keeping the memory of them alive by emulating them.
Again, while a follower of the Undying Court etc, might choose to worship their ancestors, most would not deny the existence of the sovereign host.
I was under the impression that that was regarded as a rather fringe theory.
Even though they might follow and/or worship a different deity, most inhabitants of Eberron see Arawai's hand in the harvest, and the Devourer in a storm etc.
But there are large numbers of atheists in the BoV, canonically. Whether it’s one percentage or another of the faithful is irrelevant. It’s not a tiny fringe, but a perfectly valid way to play a Seeker.
Likewise, I respectfully can’t think of any source that supports your view of the elven faiths as having any opinion at all on the sovereigns.
The people of Eberron absolutely include atheists and agnostics. There is no direct proof the sovereigns exist, and the powers of other faiths aren’t gods. Part of what sets Eberron apart is that atheism and agnosticism aren’t wild fringe theories.