Without the coincidence of 1914 and WW1, I can't see any way they can claim to be God's channel. It's the only time that a prediction sort of came true that they could tie into the whole theme of being chosen by Jehovah. Of course, this would also destroy the whole 607 timeline, further laying bare the whole rickety construct. They'd be left with the argument that they were chosen because they say so. Not very convincing.
No, I definitely think they have to keep 1914 and repackage it to fit some new light that also includes the overlapping generation. Maybe even more refinement on the old faithfull and discreet slave bit. Who knows?