Late reply in 2019: I don't think there will be even a part 3. I suspect the writers went over their head with progression (Illuminati-like organization, Conspiracy theory, Tsuchigumo backstory ...) and stuck in a block. They introduced a lot of new elements into part 2, as seen in extra story, hint at possible continuity but went silent since.
It would have been better if part 2 stopped at Uzume's will (before intervention) and Ruka's confession, so it had sort of nakige ending. Then they can continue writing and planning for part 3 with even bigger plot twists.