Can you think of any future "milestones" which will force the JWs to change doctrine (again).
I can think of a few:
1. When it can be proved that every human who has ever lived could not fit on (an even transformed) earth.
2. In 2914, Christ would have ruled for a thousand years.
(although I expect 1914 to go - long before that)
3. When there has been sufficient time for there to be no relationship whatsoever between Eve's creation and the 7000 years
(I think this can be worked out in biblical chronology from the birth of Cain and Able)
4. Something about the "remnant" dying out - oh no hold on they're increasing.
Can you think of any more?