I agree to a certain point.
In trading uncertainty equals risk, and risk in general is what investors try to minimize.
The higher the volatility, the higher the uncertainty or risk.
Longer periods of stability (lower volatility), reduce the amount of uncertainty, therefore that longer periods of stability, will more often result in a price gain than a price drop.
Especially longer periods of stability after a bubble crash, since these define a new floor.
As article the also stated, most of the investors who are more likely to sell, will already have done so.
These consolidations help establish a foundation and confidence around a given price and burn off resistance sellers.
The hidden assumption in this arguement is that past price history implies a future result. I don't believe that will always be true.
Another way to write what you wrote is there are two scenarios...
Low volatility -> price increases, then...
High volatility -> price could go either way...
If we know that level price is generally going to increase the price, then someone can profit from that; therfore the market will adjust accordingly (assuming it's efficient, which it's probably not).
Also, you assume investors generally want to avoid risk... another generalization. And if the investors only look at past trends for "riskiness," then they are already doomed to follow a simplified thought process and the masses into the poor house.