Google “Obama executive orders”, and number 1, on the day after he was sworn in, was the sealing of all his records. That was before Gitmo closing or anything else. Hillary is probably one of the few that knows everything and she is Sec of State. If Biden retires and Hilary takes his place, you will know. Then Arkancide is close by. Who’s gonna know?
The Sec’y of State is next in line to succeed to the Presidency, after the V.P., but that doesn’t mean that the Sec’y of State becomes V.P. if the V.P. becomes President.
If Obama leaves office or dies, Biden becomes President, and then Biden would nominate a new V.P.