> Reversion to the mean, also called regression to the mean, is the statistical phenomenon stating that the greater the deviation of a random variate from its mean, the greater the probability that the next measured variate will deviate less far. In other words, an extreme event is likely to be followed by a less extreme event.

It is a stretch (and invalid, generally) to extrapolate this well-defined phenomenon to a complex system. There are many complex systems that maintain or increase their complexity.