Joe, presidential candidates that win their primaries get access to classified information and discussion with generals over the future of national defense within days of winning a nomination. He'd have had this since April...
this policy started in 1952 so if the non-incumbent won they wouldn't be scrambling to learn about national defense measures before their inauguration. Truman created this policy because he was only informed of the Manhattan Project 12 days AFTER he took office
this was a big discussion point in 2016 when Harry Reid (RIP you psycho commie) tried to keep Trump from gaining this access.
This also includes NG standing at attention when a private citizen enters the room.