From my standpoint, this is nothing but the prevalence of the ideas that Bernanke has worked on during his whole academic tenure. Actually, one of his first contributions to the economic literature was to prove the strong links between the liquidity squeeze in the banking system and the credit crunch that led the U.S. economy to the Great Depression.
He also deeply studied the particular issues of monetary policy under stress such as the zero nominal interest rate case. Ben has insightful knowledge on how liquidity constraints in the banking system could translate into problems in the real economy. He thoroughly acknowledges the boundaries of monetary policy that only have interest rates as a tool.