I wouldn't overstate the effect of these stories. To us on this forum, the JW leaders are a tyrannical bunch of liars who ruined our lives. To the media, and most newspaper readers/TV viewers the JWs are a very small and mildly irritating religion.
The stories may help to shake out some Witnesses who may already harbour doubts about the rationality of their leaders, and make them feel uncomfortable about remaining closely aligned with them. They may also make some people who atre contemplating baptism or home bible study to walk away from it. The key message in these stories needs to be that once you join, they will do everything they can to make it hard to leave, including name calling and organised shunning.
The stories help to chip away their support and keep the idea of "cult control" in the minds of casual readers. But the reality is the publicity isn't going to bring this religion to its knees.