These "gifts" often come with restrictions. Mostly it is about how long the materials can be held out of general public view. "Scholars" or researchers frequently can be given "access" but are prevented from directly quoting or copying anything. This access is often controlled by the person/estate that made the gift. It's been 8 years. I suspect the typical restraint is for another 17 years. He's probably be dead by then, and no one will really care. Furthermore, now that he'll have a "presidential library", I suspect that these materials will somehow be folded into his overall political record.