I predict his file will be incredibly boring/banal stuff, with the odd wild conjecture. The blacked out parts will consist entirely of things embarrassing to the agents who compiled it.
It would have the potential to be valuable in the future, if nefarious acts came to light via some other method, because it would potentially show that possibly illegal actions were taken to hide the information. However, if nothing actionable is ever discovered about this case, then the redacted documents would be completely worthless. Only time will tell.