By definition, Top Secret information would cause “exceptionally grave damage” to national security if disclosed.
Revealing that the leader of the most powerful nation on the planet is completely incompetent would be quite damaging. Of course, that cat’s been out of the bag for years, so this is an obvious ploy to save Biden from embarrassment in a election year. Campaign commercials with a confused candidate mumbling and slurring incoherently would be damaging. They just want this to go away.