They are. Hellknight Hill comes out at the same time as Midwives to Death.
It seems the article is based on old information then. Breath of the Dragonskull quite explicitly states that he's the eidolon of the god caller in question now.
James Jacobs wrote:
What about a cult of Cthulhu? Would Minata be the place where it's most likely to find one?
The back matter article of PF24 mentions at least 3 other protean lords by title. Planar Adventures has more information about the Speakers of the Depths and the Godmind (the former is a full deity with domains and subdomains provided, and the latter is not a god at all).
The Gold Sovereign wrote:
Plus the Speakers of the Depths and the protean lords. I don't think the Outer Gods and Great Old Ones have this sort of dynamic.