“Trump has the authority to declassify and transfer to his personal ownership”
NO, that is FALSE!
The sitting President has the authority to order certain documents to be declassified. He cannot perform the required steps himself. It has to be done by proscribed government employees according to set procedures.
He does not get to transfer the documents to his personal ownership, leaving the government without ‘originals’ (what is an original in this era of digital production, unlike in the age of carbon copies) as opposed to making and taking copies of truly declassified documents to be owned personally.
No President can proclaim something declassified and it is then so. Not how it works.