Perhaps in time there might be a dissenter but I reckon the GB members are picked VERY carefully to make sure a "Franz Incident" doesn't happen again but you never know.....
Ray Franz has done a great deal of damage to the Society with both his books. If he had ranted and been bitter in what he published, he would have been quickly dismissed as a loon by those seeking answers, but because he showed reason and fairness, many have read his books and realised he was right.
There is no doubt in my mind, I believe Ray was led out of the Watchtower by God. His ministry, if you like, was writing those books and personally helping thousands to come to terms with leaving such a high control group. I have a great deal of respect for the man.
But he's getting on now, over 85 I think. His books will stand the test of time for a while longer but they will gradually date. I think if God deems it necessary, and sees the heart of a reasonable man on the GB, then I believe he will lead that one out of the Watchtower to be used to help others, just as Ray was.
If not, then I reckon the WT Society is in its death throws now and another "Ray" won't be necessary. The whole thing will crumble at once.