This would create a new dynamic in the global monetary order, one in which central banks would struggle to implement monetary policy.
They say this as if they are currently able to implement monetary policy. Central banks around the world is starting to run into walls as far as their monetary policies are concerned as they no longer have the effects they used to have meaning that they are running out of 'tools' to use to 'manipulate' the markets.
Bitcoin and or blockchain currencies cannot be blamed for this, they only have themselves to blame. If you manage the economy like a neanderthal then you should not be surprised if people move on to other 'currencies' which are worthy of their trust.