Java, even without considering Poincare recurrence it approaches certainty that parts of the universe will have decreased entropy through chance alone. Again, this goes back to thermodynamics being completely probablistic.
Consider what happens when you knock a billiard ball into a pocket in a pool game: the ball loses energy rolling across the table, converts its gravitational potential energy to kinetic energy as it falls, converts *that* energy in the collision with the pocket in the form of sound, heat, and the deformation of the ball's structure -- so on and so forth.
What's to prevent the ball from jumping back onto the table and rolling back to the cue stick?
In truth, nothing is besides statistics. If all the sound energy, heat energy, elastic energy and so forth were applied to the ball in the same places where they left it, it would have exactly the right amount of energy to be propelled up onto the table and roll over to the tip of the cue stick that originally knocked it in.
The interesting thing is that if some physicist were to watch these interactions happening on an atomic level, nothing would look different: there would be no way to tell whether the tape was rolling backwards or forwards (so to say). The arrow of time only gets its meaning from the entropic gradient, and the entropic gradient only gets its meaning from statistics.
Given an infinite amount of time, anything with a non-zero probability of occurring approaches certainty of happening: furthermore, it approaches certainty of happening infinitely often.
What is the probability that some pocket of the megaverse will reduce its entropy enough to look something like a big bang or like the visible universe we're familiar with today? It's so exceedingly, laughably small that it might as well be zero -- but it's not zero. Since we're talking about the possibility of an infinite time span, it then approaches certainty that yes, even given the heat death of the universe, there will eventually be pockets that reverse their entropy through sheer chance alone all the way to Big Bang Event states an infinite number of times.
This is not the same as "cyclical universe" models with a Big Bang and a Big Crunch; though there are some similarities.