They need to stop calling themselves "The Truth" and "God's Channel". Because if new blight contradicts their old blight, then they certainly do not have the truth nor can they be God's Mouthpiece (unless God is messing with them... or God doesn't exist and it's just all crap their pulling from their a$$e$).
I had an interesting exchange with my parents on this. Back in my 20's, with both of my parents present I asked them outright "Is the Watchtower God's chosen organization, his sole channel of communication?" (You can probably guess where I would be going with this as it doesn't really matter what the answer is... Botchtower is just another religion serving up BS as Truth ... and hurting people in the process).
At exactly the same time my Mom answers "Yes." and my Dad answers "No."
The holy shit look that passed between them was priceless. So much for unity. I gave them the eyebrow.