Russell didn't learn, Rutherford didn't learn, Knorr didn't learn, the GB doesn't learn...
Interestingly, the Awake Mar 22 1993 stated that the Millerites were not false prophets (of course they had to state that otherwise, they'd be putting their shoe in their mouth):
William Miller, generally credited with founding the Adventtist Church is quoted as saying "I am fully convinced that sometime between March 21, 1843, and March 21, 1844, according to the Jewish mode of computation of time, Christ will come."
Does the failure of such predictions to come true convict as false prophets those who made them, with the meaning of Deuteronomy 18:20-22?... [quotes the scripture]
There are some who make spectacular predictions of the world's end to grab attention and a following, but others are sincerely convinced that their proclamations are true. They are voicing expectations based on their own interpretation of some scripture text or physical event. They do not claim that their predictions are direct revelations from Jehovah and that in this sense they are prophesying in Jehovah's name. Hence, in such cases, when their words do not come true, they should not be viewed as false prophets such as those warned against at Deuteronomy 18:20-22. In their human fallability, they misinterpreted matters.
I wish red flags had been raised when I first read this article. Guided by spirit but repeated "human fallability"... hmmmm...