That line refers to the mechanism to prevent double spending. If the network needed a centralized controller to assign an ordering to transactions and ensure co

That line refers to the mechanism to prevent double spending. If the network needed a centralized controller to assign an ordering to transactions and ensure consistency, that would run afoul of Satoshi's vision. But centralized exchanges are merely users of the base network just like an individual broadcasting transactions themselves. They depend on network consensus just like everyone else.