Even if Trump declassified the documents before he left office, this wouldn't change the nature of the documents or the information in them.
From the 11th Circuit decision:
>>>
the declassification argument is a red herring because declassifying an official document would not change its content or render it personal. So even if we assumed that Plaintiff did declassify some or all of the documents, that would not explain why he has a personal interest in them<<<
The court's statement is in the context of Trump's request for return of the documents. In order to prevail, Trump would need to prevail based on the factors listed in Richey v. Smith, 515 F.2d 1239 (5th Cir. 1975).
This is Richey factor (2) listed in the 11th Circuit decision:
>>>The factors a court should consider when deciding whether to exercise
jurisdiction include (1) whether the government “displayed a
callous disregard for . . . constitutional rights” in seizing the items
at issue; (2) “whether the plaintiff has an individual interest in and
need for the material whose return he seeks;” (3) “whether the
plaintiff would be irreparably injured by denial of the return of the
property;” and (4) “whether the plaintiff has an adequate remedy
at law for the redress of his grievance.”<<<
Nevertheless, the court's statement that "the declassification argument is a red herring because declassifying an official document would not change its content" undoubtedly applies to the criminal laws, Sections 793, 2071, and 1519, listed in the search warrant:
>>>Because Section 793 predates the modern system of classifying sensitive material, it does not use the phrase classified information. Instead, the statute protects information and material “relating to” or “connected with” national defense—often called national defense information. . . .
Another statute cited in the Mar-a-Lago search warrant and affidavit is 18 U.S.C. § 2071, which generally prohibits, among other things, willfully and unlawfully concealing, removing, mutilating, obliterating, or destroying a “record,” “paper,” or “document” that is “filed or deposited with any clerk or officer of any court of the United States, or in any public office, or with any judicial or public officer of the United States.” . . .
The Mar-a-Lago warrant and affidavit also lists 18 U.S.C. § 1519—a statute criminalizing certain acts of destruction of evidence in obstruction of certain federal investigations or proceedings. Congress intended § 1519 to have a broad scope, and prosecutors have used it to charge an array of behaviors aimed at undermining investigations, including creating false reports, hiding objects, and shredding documents. <<<
https://crsreports.congress.gov/product/pdf/LSB/LSB10810
In other words, as of right now "declassification" is completely irrelvant to any legal issue that has been raised by the DOJ.
Having said that, Trump would need to prove he declassified the documents if the DOJ were to indict him on
additional charges under Section 1924:
https://www.law.cornell.edu/uscode/text/18/1924
If the DOJ indicts Trump under Sections 793, 2071, and 1519, I'd expect them to also indict him under 1924.
