They may have found votes being changed in a primary or voters erroneously add to purge lists. I saw a few clips, and they made a point to emphasize that they wouldn't be addressing 2016. They repeatedly said they are working against the Russians now. It can't be that Russian's gaining access to voting systems etc. Since we already know they've done it and continue to try.

A reporter probably asked them for comment on the upcoming expose. They asked the report for twenty-four or forty-eight hours to get out ahead of the story.