>>Why is this important [to drop] prior to BO testimony?<<
IMHO, maybe it's to push BO/them into panic and force them to make misstakes. BO is testifying tomorrow. I bet he organized his thoughts,had answers to probable questions, got 'his' story straight, and then BAM! This shit comes up and fucks his whole world up. Now there is evidence and things coming to light, and he's not really sure what /we/ know at this point and a cherry on top is…. In less than 24 hrs, he is to testify under oath.
Hard to get 'your' story together on such short notice!