The president decides what’s classified or not
The espionage act does not depend on any classification regime. Your point is moot.
Moreover....
NDI docs depend more on DNI damage assessments (which will have a bearing on sentencing, if found guilty), if anything, and their classification is an asterisk to the assessments. Moreover, the prez has NO authority to reclassify a nuke doc without coordination with the classifying source, per the ETA. and Trump had at least one nuke doc in his possession. Possession of that doc, alone, will get your 5 years.
Additionally, even if he reclassified a bunch of docs, they still belong to the government. The PRA gives final say on what docs belong to the gov to the archivist.
Additionally, Trump is making these claims of 'reclassification' as a private citizen, which he has no authority to do. If he had reclassified anything during his presidency, he would have to prove it, and since, even if he did, that he did not follow any of the standardized memorialization protocols, therefore, he can't prove that he did, and as a private citizen, and unless he can prove it, those docs are classified to whatever the docs say on the docs. But, it doesn't matter, the docs still belong to the government and their theft, and aggravated circumstances (obstruction the government's efforts to retrieve the documents) has resulted in a violation of the espionage act.
All that being said, none of it matters, per the first sentence, above.