As to the inoculation effect I can only say that on my podcast, which has far less reach than Leah's show, I've had people reach out in emails telling me how much they appreciated knowing more about what JWs are really like. This show will just be another outlet, another voice, another time, and will no doubt help inoculate at least some of the public. If this jackass sitting in his basement on a mic can do so, surely she can at a greater level.
People still advertise that they do windows or roofing or whatever. Why bother, since we all know how to find such companies? Because the right message at the right time brings in some customers, not all, but more than you had to start.
People will still become JWs. The goal can't be to prevent everyone everywhere from doing so. But it will help some people, and if that isn't good enough then I might as well shut down my podcast, this site should close down, etc. But all of these things get in front of different people and help someone out there.
If nothing else, I'd you believe that no measurable good comes from it, it doesn't seem to be doing harm unless you feel there will be a backfire effect and people will start flooding Kingdom Halls.