I think that the policy of treating all DFd persons the same, regardless of whether they are anti-Witness or promote other doctrine, results in an increase in the unintended consequence of more "apostasy".
Think about it: If they said you could still casually associate with those who just left the religion but keep their mouth shut, and the only ones who were seriously shunned were the ones who were speaking out against the Witnesses or against doctrine, how many people would be choosing to keep their mouths shut for the sake of maintaining their friends and family?
But as of now, it doesn't matter. Everyone DFd is lumped the same. So why not say what you want if you get DFd? Why not make youtube videos and hold protest signs?
If the WT was smart, they could be using that to their advantage, the way they use DFing now to keep people in. They could also use it to keep people who have left in line.