Barr is a red herring.
They will use the FinCEN Suspicious Activity Report leaks as the basis for a lightning impeachment of POTUS, which will tie up the Senate so they can't act on SCOTUS. That, in turn, will lead to a constitutional crisis post the election when Appelate decisions can't be reconciled by a 4-4 SCOTUS.
I think this is how Buzzfeed and others plan to "get" POTUS, by uncovering and publishing SARs tied to Trump organizations.
They get to decide what they release, and when. They've already said they are going to release selectively.
https://www.buzzfeednews.com/article/jasonleopold/fincen-files-financial-scandal-criminal-networks