It makes no sense what so ever that any all intelligent God would decieve so many people for so long with one truth, then change the truth right before his great day of judgement. That would be ridiculous and very sick.
But it happened before when the Watchtower Society re-invented itself in the wake of failed predictions.
During the mid-20s, and especially after 1925, the religion lost up to 75% of its membership. And, in retrospect, the loss was orchestrated - it, too, was a divide and conquer maneuver that paved the way for a brand new religion to rise from the ashes - the Jehovah's wintesses AKA Joe's Army.
Failed predictions don't harm this religion - the failure of 'biblical' prophecy (AKA political doctrine) is a boon to the 'Organization' - it acts to get rid of those who are not LOYAL and OBEDIENT. Because, the only thing that the membership does for this organization is give it just enough legitimacy to keep operating under the guise of a religion. The Watchtower Society will and can continue operating even without membership - the only thing that would change is that they would go into a different tax exemption category (and they would lose the built-in 'volunteer' group that will sign up so readily for medical studies..but that should be no problem once 'blood management' is rolled out worldwide - the Society won't need that noblood control group anymore).
A great 'falling away' will actually help this religion in the long run. The current Jehovah's Witnesses (and the burdensome apostate community that comes along with the group) can eventually fade away and become as invisble to the membership as the Bible Students did, way back in the day. Most current JWs have grown up with the notion that the JWs are the core group and the Bible Students just simply....disappeared. This can, and will, happen again.
However, it was probably a lot easier back in 1920s to re-emerge from the dust of legal and political intrigues that happened behind the closed doors of the Society. Today, tax laws and such make it more difficult to pull off a costume change privately - the door to the dressing room is not as closed, especially with an active apsotate community that keeps opening it on them.
Something that may be giving the Watchtower Society some difficulty is the low membership numbers. A total global membership of only 7 million - a tiny group, actually, in the whole big picture. Why this could be problematic is that the tax man might be questioning how such a small membership can sustain such a large, multi-billion dollar establishment. I don't know what the total worth of the Society's properties and investments are, but, it more than exceeds what can be accounted for by donations alone. Which might be behind the 'attack' that the GB claims is occuring in headquarters - the tax man could be asking some pertinent questions as to where all the money comes from. The below average earnings of the r&f just doesn't cut it as an explanation to the tax man/charity commisssions for their overflowing coffers.
But, never fear...the Society will scramble, hide, and generally pull all sorts of illegal maneuvers to keep their operation afloat - including alienating the membership and fishing for a whole new (or almost new) slice of the marketplace through their re-branding.
Changing the religion is a solution for them, not a failure.
And the Watchtower Society won't disappear - it will just re-invent itself. Like it always has done.