Perhaps the whole reason to release this, is to try to blame Republicans for Islamic Terrorism (i.e. Bush covered for the Saudis). The timing is probably to distract from the Republican Convention, and reduce Trump’s bump from it.
The Democrats are very vulnerable on this issue, and at least need to muddy the water, even if they can’t fully shift blame.
Alternatively, they are releasing it on a Friday prior to the convention, just to minimize coverage, and keep the islamic terrorist issue off the radar.
Very good points. I agree with you.