At the beginning of the week AG Barr very publicly stated that he "doesn't expect" criminal charges against Obama and Biden. But that was very quickly followed by the bombshell Rice declassification. The Rice email-to-self, far from exonerating Obama (as Rice must have intended), shows Obama very closely involved with the coup conspirators--plotting against Flynn and thus against Trump himself.
Was Barr sending an equally public message to Obama? If so, that message may have run something like this:
"Look, as a former president we can give you a pass on your involvement and confine our criminal charges to the triumvirate: Brennan, Clapper, Comey. We're prepared to do that, but know this: If you don't back off from public interference with our investigation, life could get a lot more unpleasant for you going forward. Don't count on us not having more than just the Rice email. And know from this--the revelation of the Rice email--that we're ready to use what we have. It's up to you."
Bill Barr is the guy who's ultimately in charge of all this. He's AG, and he guides Durham. He also has authority over all declassifications. When Grenell shows up at Main Justice with a satchel of "stuff", count on it--it's all been carefully calibrated and orchestrated. None of this--not the events and not the timing--is happening by coincidence.