It'll be extremely difficult for Zulqarnain to brave concerns regarding the security of his family and reveal names, especially after the threats they have received today.
Even Mohammad Aamer promised to be the whistleblower a few weeks back, but as of now, we haven't heard a word from him with regard to the match-fixing scandal.
Don't forget that the antagonists in this case are rich and viciously powerful, and they'll pull out all stops to prevent someone from making their names public. I'd be rather surprised if this guy doesn't renege on his word and actually goes on to blow the lid off the wrongdoings.