People like Barbara and Bill have done immense work exposing what was already a problem. The publicly known cases are from the 1980's and 1990's so could not have been prevented. However the fact they have strived to make them public has hopefully given others courage to go to court and testify against their abusers including WTBTS.
It would have been inevitable that these ones be DF'd as their consciences were opposed to the rules laid down by WTBTS. It may be a few years before we see how prolific paedophilia still is in JW land, the so called spiritual paradise.