Um, because he said it publicly, and it would be easy for anyone on the Democratic side of goverment to show that he lied about it?
Maybe that’s what tomorrow’s press conference will be. Maybe the ‘resistance’ inside the goverment will come out and say that Trump lied about declassifying everything, and that the stuff being declassified is selective to help him. Or that they are refusing Trump’s orders because of harm to national security and offering their resignations or something.
But the idea that Trump would say he’s ordered the declassifying of everything when he didn’t doesn’t really pass the smell test for me. Too easy to check. But I’m sure we will find out shortly.