It's a good question. Those are second order digital money. They are not actual assets or liabilities on the central bank balance sheet. They are digital ious

It's a good question. Those are second order digital money. They are not actual assets or liabilities on the central bank balance sheet. They are digital ious on a bank's balance sheet. The difference here is that the asset and liability are moved directly onto the central bank balance sheet. The reason this matters is because CBDCs are fundamentally about creating a hybrid fiscal /monetary policy tool that the central bank can use and allowing the central bank to digitally alter the balance sheet in a way that affects retail customers is the only thing that enables that. As a side note, there is nothing which intrinsically ties these to crypto or block chain. You could implement this without either of those concepts.