Those sneaky bastards... Without making a big announcement so that we would know, they released the third OST almost two months ago!
https://www.youtube.com/watch?v=w4srkndzvKo
...I'm pissed off that, after three OSTs, we still don't - and likely never will - have an official release of the creepy choir-and-pipe-organ track that played during Naruto's first 4-Tailed Form transformation and also right after Pain stabbed Hinata.