There was already an outstanding FBI investigation. He didn't give anything to the FBI they didn't already know. The investigation was wrapping up by that time. So Cantor did the right thing. The WH will say they didn't make it public until after the FBI investigation was over.
The only thing left of interest to me is whether evidence of blackmail by the WH still exists. I doubt it. If there is no blackmail evidence then this story eventually dies away