Why or why not? Trump said he already did but then his people squirmed out of it for him.
Might as well declassify everything in the Federal government. After four years of Trump, the US has no secrets our enemies don’t already know.
The one thing you don’t declassify is sources and methods. So if for example there was a note in there about how we learned something courtesy of a listening device in Putin’s office or because his secretary works for the CIA that will remain under black bars.
I believe there were other things that were left out because of ongoing investigations as well. I am not sure how that works (or if any of these investigations are still ongoing or will be resumed in the Biden administration) but I can picture not wanting to tell Jared Kushner in advance which documents he should be shredding if he doesn’t want to go to jail.
I was going to exempt sources and methods in the OP and probably should have. Also, its understandable to not tip your hand in ongoing investigations but I’d bet the farm that there is plenty that was classified that doesn’t fall under either of those. “Merely embarrassing” doesn’t qualify for classified status, although it probably covers most of everything that has ever been given that status. No proof on my part - just a hunch.
Establishing early on exactly how corrupt the Trump admin is/was is important enough for the US and the rest of the world that they should probably just suck up any impact this might have on continuing investigations. Schedule a time to arrest everyone you can, and then charge then with whatever you can based on the information on hand, and then release the report. We might not get every scumbag, and probably won’t charge every crime they’re actually guilty of, but they’ll at least have a very uncomfortable time in court and jail, and we’ll get to see what was really in the full report.
Release anything that isn’t a legitimate national security concern. Dig into that super-dee-dooper server and fish out the complete transcript of that infamous call with the president of Ukraine. Get the Russian translator to testify as to his recollection of all the conversations between Putin and his blond stooge in the White House.
Stooge - O.K. but blonde? I that what you all that?