My problem with this is that Warlocks, practically by definition, are dealing in pacts with non-divine beings. A "Celestial Pact" Warlock (though straining plausibility, for me/my game world) fits. A "Divine Pact" Warlock is just that one step, flavor wise, too far...or maybe "too close" to Cleric for my liking.
As for the Sorcerer option...this just falls under the "family ancestry" we have been given in the Draconic Sorcerer. We don't acutally need Elemental Ancestry, Genie Ancestry, Divine Ancestry all as separate sub-classes...Just take the dragon sorcerer and swap out other powers of similar potency at the appropriate levels that, flavorwise, fit whatever your ancestry of choice is. We have the "Innate Magic/Powers from Ancestry" sorcerer already.
Then we have the "Innate Magic/Powers from the Random/Raw/Chaos of Magic"...still a fluke of birth, but with a different angle than "Grandpa got down with <insert magical being here>." If we see a new sorcerer, I suspect/would like it to be the Psychic/Psion: "Innate Magic/Powers from the Mind"...again, innate, again, a fluke of birth, but again, the basis of the power is not just "Great Grandmama was a Djinn/Storm Giant/Elf Uber-Wizard/Sylph/Gold Dragon."...unless, of course, that's what the player wants as flavor part of their back story but it isn't really the base of their power.
...I seem to have gotten myself on a tangent here...but, yeah, the Divine Warlock isn't really an archetype I could see myself (or many plaers) accepting except/unless it is within a given setting consistency. Not a universal one, though.