It is futile to try classify information which has been broadly disseminated, true. But that does not apply to docs that someone has, but has not yet published.
Declassification in Reverse - The U.S. Intelligence Community’s Secret Historical Document Reclassification Program
https://nsarchive2.gwu.edu/NSAEBB/NSAEBB179/index.htm
Washington, D.C., February 21, 2006 - The CIA and other federal agencies have secretly reclassified over 55,000 pages of records taken from the open shelves at the National Archives and Records Administration (NARA), according to a report published today on the World Wide Web by the National Security Archive at George Washington University. Matthew Aid, author of the report and a visiting fellow at the Archive, discovered this secret program through his wide-ranging research in intelligence, military, and diplomatic records at NARA and found that the CIA and military agencies have reviewed millions of pages at an unknown cost to taxpayers in order to sequester documents from collections that had been open for years.
The briefing book that the Archive published today includes 50 year old documents that CIA had impounded at NARA but which have already been published in the State Department’s historical series, Foreign Relations of the United States, or have been declassified elsewhere. These documents concern such innocuous matters as the State Department’s map and foreign periodicals procurement programs on behalf of the U.S. intelligence community or the State Department’s open source intelligence research efforts during 1948.
What you identify is interesting, but would never survive the light of day if anyone tries to enforce it, especially now. How do we know this? Because earlier attempts to do this have been furtive. They know it's absurd to attempt to illegalize history.
The intended parallel the spooks you cite have been trying to invoke is the one that says, if the password to your bank account or the combination to your locker has been breached, you change it, to keep it safe. That pertains to information that is by its nature private and in current use.
But a truth of the past that has been revealed can't be unrevealed. Is anyone with whom it has been legally disclosed now suddenly obligated to work for the State? No civilian court could support that, because it would open the way to banning someone from repeating any known fact at any moment between now and the end of the world. There would be no separating this restriction from political speech or religious speech.
If this idea of has on-again, off-again classification been practiced in secret among spooks alone, that's one thing. But the Presidency is intentionally a public, civilian office elected by civilians. He has access to the military because he represents their boss--the people. The whole point is the people have a military, and not the other way around.
If someone has to go to the trouble of bringing this idea of "re-classifying" historical fact from a previous administration to the Supreme Court, it will not survive a half-hour's discussion. Remember the Pentagon Papers? It's the Left's favorite case--not that they'll want to be reminded about it now.
“Washington, D.C., February 21, 2006 - The CIA and other federal agencies have secretly reclassified over 55,000 pages of records taken from the open shelves at the National Archives and Records Administration”
Trump may have declassified documents pertaining to Russia Collusion and took them home with any mass distribution occurring. Biden comes along and reclassifies the docs.
Just a theory. Not sure that even happened but it could explain what is going on here.