Predictions are always perilous. Many of us recall the hearty enthusiasm of the Bowen report of 1989, which assured prospective graduate students that they would find "a substantial excess demand for faculty in the arts and sciences" when they earned their degrees in the mid-1990s. Of course, they did not.
Moral: Avoid confident assertions about the future of the academic job market in the humanities (or in any other field). It may be that our current dilemma is another episode in a longish cyclical history. It may also be, as I rather pessimistically suspect, that something more serious is going on.
My reason is that just about all of the key drivers are simultaneously pointed in the wrong direction. Full-time tenured and tenure-track jobs in the humanities are endangered by half a dozen trends, most of them long-term.