It would seem to me that he is talking about Poincare Recurrence. Basically a physical concept of "If you made a monkey type on a keyboard for an infinite amount of time, at some point in time, the monkey would coincidentally type out any book that has ever been written." Except in this case, with conservative entropy systems returning to the initial state. Billions of years are not anywhere long enough to achieve this.
Here is a good read on the Poincare Recurrence: https://physics.stackexchange.com/questions/94122/is-poincare-recurrence-relevant-to-our-universe