Bakker or his publishers haven't offered any confirmation yet, but it appears that The Unholy Consult has been split into two installments. The third volume in The Aspect-Emperor series, now titled The Great Ordeal, is slated to be released on July 5th 2016.
Here's the blurb that one can find on Amazon:
The much-anticipated third installment of R. Scott Bakker’s acclaimed series, The Aspect-Emperor.
Praised by fans and critics worldwide, R. Scott Bakker has become one of the most celebrated voices in fantasy literature. With The Great Ordeal, Bakker presents the long-anticipated third volume of The Aspect-Emperor, a series that stands with the finest in the genre for its grandiose scope, rich detail, and thrilling story. As Fanim war-drums beat just outside the city, the Empress Anasurimbor Esmenet searches frantically throughout the palace for her missing son Kelmomas. Meanwhile and many miles away, Esmenet’s husband’s Great Ordeal continues its epic march further north. But in light of dwindling supplies, the Aspect-Emperor’s decision to allow his men to consume the flesh of fallen Sranc could have consequences even He couldn’t have foreseen. And, deep in Ishuäl, the wizard Achamian grapples with his fear that his unspeakably long journey might be ending in emptiness, no closer to the truth than when he set out. The Aspect-Emperor series follows Bakker’s Prince of Nothing saga, returning to the same world twenty years later. The Great Ordeal follows The Judging Eye and The White-Luck Warrior, and delivers the first half of the conclusion to this epic story. Returning to Bakker’s richly imagined universe of myth, violence, and sorcery, The Aspect-Emperor continues to set the bar for the fantasy genre, reaching new heights of intricacy and meaning.
Will try to reach Scott to see if we can learn more about this. . .