A "standing order" is not how the classification of documents is changed.

"Merely proclaiming a document or group of documents declassified and doing nothing more would not suffice," Bradley Moss, a Washington, D.C.-based lawyer who works on national security cases, told PolitiFact.

Follow-through is required.

"He had to identify the specific documents he was declassifying, he needed to memorialize the order in writing for bureaucratic and historical purposes, and he needed to have staff physically modify the classification markings on the documents themselves," Moss said. "Until that was done, the documents, per the security classification procedures, still have to be handled, transmitted and stored as if they were classified."

Tom Blanton, director of the National Security Archive at George Washington University, agreed.

"If the documents are still marked classified 18 months after their removal from the White House," Blanton told PolitiFact, "then Trump was too busy to order them declassified at the time."

https://www.politifact.com/article/2022/aug/11/could-trump-argue-declassified-documents/

But in any case it will concern many republican voters that national secrets were taken to mar-a-lago and held in an unlocked room for a year by an ex-president. Whether or not the person taking them claimed to have changed the classification without telling anyone.