The problem is when the faithful hear something at the Kingdom Hall they believe it as if was from god. So anything can be said and the zombies will comply. This means the ones leaving are the ones on the fringe and the young. The cult will go down but ever so slowly.
The good news is they keep putting their foots in their mouths helping to wake up more people Also the numbers of old JWs that are going back seam to be falling way off. Once your out, faded or dfd it's easier to see the problems with the cult or get online to do research. People just aren't going back like they used to.