I personally suspect they already have the e-mails and are just trying to prod players to come forward to save themselves by providing more evidence.
Given what appears to be a media shift on this topic, you’re probably right about the emails and the media has gotten a whiff of what’s there.
I personally think you are quite right. Spreading this out before dropping the hammer (1) makes complete liars of the prominent D players, (2) compels the media to follow, or look like the stooges they are, (3) compels, however reluctantly, Justice to become involved, (4) keeps 'big, tyrannical government" front and center as election approaches.
I think they have all the emails they need - and have had them for awhile. This is about doing real damage to our enemies - all of them.