I wouldn't say automatically. There are a number of things that would prevent historical documents from being published. Things related to national security that sit within Library and Archives, for example, all prevent them from being published.
I guess this is where I allude to some of the interesting things that Library and Archives is doing that are outside the scope of access to information. They've had a very interesting system of block review, going through files and boxes of old things that have not been released and just kind of selectively picking out some to see if those batches contain any information that couldn't be released under the act. They have released millions of pages, from what I understand, of historical documents as a result.