They've always said they were not infallible. It's the saying they make mistakes that feels different. The old way was getting clarifications which in fact were complete reversals of previous positions and not "clarifications" at all. But, they never couched it in terms of a "mistake" only a "new understanding".
The more I think about this, the more I wonder if there is a major change coming.
But, the average JW WILL NOT CARE! Seriously, there may be a few that get awakened just like with the last crazy "adjustment" with the generation. But, I'm not sure if at this point, anything they say or do would cause a major fallout. As a matter of fact, I would venture to guess that any major doctrinal adjustment would either 1) go over everyone's head or 2) get people more enthused for a short period.
Cults change things all the time to keep people off balance. And so the GB will continue to make changes big and small and the beat will go on. Eventually this religion will bleed out by a thousand cuts but it will be a slow fade into the dark night and that will take several generations (real ones not their definition).
I hope I'm wrong but I don't think I am.