This could turn into a royal "he said / she said".
Trump needed somebody to memorialize what he said, so they have an official record of him saying it.
Without that official record, any claim Trump makes now, is meaningless.
That's why there's a presidential records act. All presidential actions are supposed to be documented, and the National Archives becomes the repository of the proof.
I doubt Trump will ever be charged with anything. From what I can glean from various stories is that Trump's lawyers and the national archives were winnowing through things with several files having been returned by Team Trump earlier this year. Trump then officially designated the Patel guy as his archivist. Patel apparently did some conservative friendly media saying he was releasing all this stuff to the public via an online database similar to wikileaks after getting into some behind the scenes pissing match with the National Archives and soon thereafter the search warrant happened. I assume the National Archives is moving to scuttle any attempts by Patel to release ANYTHING in Trump's possession that has not been properly and fully declassified by the book with all i's dotted and t's crossed.