That doesn't seem right. The hash rate drop followed the price drop. It was just loss-making miners shutting down. The hash rate stopped dropping after the price stopped crashing. How is the hash rate predictive of anything?
It was exactly same in 2011 and in 2014. Few weeks before bottom happened.
That doesn't prove the bottom is in. It just proves hash rate drops when price drops. When price stops dropping, so does hash rate. Any local bottom (or long term bottom) will have this dynamic because there is a direct relationship between price and mining profitability.
But you have no way to distinguish between a local bottom (like a bear flag before new lows) and a long term bottom (like 2011). If we crash again to new lows, hash rate will probably crash again too.
In other words, price predicts changes to hash rate, not the other way around.