It sounds like they were given an offer they couldn’t refuse:
Turn over the documents, or turn in your resignation.
Precisely!
I doubt it was resignation. Wondering if it was to be some sort of obstruction charge.
And...I'll declassify everything so the public sees all of it, unfiltered, in October!
Probably more like: Turn over the documents or Ill declassify everything soup to nuts.
(They want Trump to ask for their resignation.)