Guess this means my dreams of Lolth being reverted back to a potent demon lord, and not being a god at all, are dashed for at least one more edition.
Ah, well. It's not too late for Vecna to be just an ancient, legendary lich again, or Tiamat the queen (but not goddess) of chromatic dragons.
I agree, with the exception of Tiamat, I've always used a mother of monsters, primordial sea, Babylonian vibe for her so goddess is fine.
Actually, I use her as a fundamental part of the cosmos, above the disturbingly mortal like gods with flaws.