There is another way to think about this. With 1914 fading into oblivion, it can seem distant to the point that it ISN'T questioned.
Overlapping generations still has an expiration date on it. Lets say the oldest annointed person is 40 which would be very young. The end has to come before that person grows old and dies according to the new doctrine.
So the GB has explained away the number going up by calling them loons, consolidated power making the annointed impotent, then simultaneously will point ot the number as proof of the overlapping generation and that we are still in the "last tick of time".
As 1914 gets older, I think it might just end up making people more lazy as to its significance. And I also do not think it is going anywhere. 1919 is dependent on it for example.