Ghost's Popestar tour just wrapped up on November 12, and the band hasn't exactly been secretive about the fact that it's working on a new album. The new album has a very tentative and broad release date for fall 2017, though the arrival of Papa Emeritus IV might be way before then. The video below with Sister Imperator discusses the rise of a new entity, the band taking up its instruments and rising once more, and closes out with the message "are you ready…" Not to mention Imperator literally says "the fourth incarnation," which couldn't be more cut and dry.
So maybe we'll get one more small tour in there before Papa Emeritus IV rises? Generally when Ghost unveils a "new Papa Emeritus," it's at a special show, the band plays some new music, and there's information about the album shortly thereafter. So who knows what Ghost has up its sleeve this time… but the video below sure as hell makes the coming of a new Papa pretty evident.