He's right. It makes very little sense for state actors to block-chain-ize their fiat currencies if they are not intending to fundamentally change their financial structures and policies. Cryptocurrency as an asset class is not compatible with central banking. You certainly could offer a blockchain alternative to a national currency, but it wouldn't change the underlying value of that currency if it continued to operate according to central banking practices. It might shift certain jobs in accounting and finance, but it wouldn't fundamentally change anything. Electronic exchanges are already recorded and tracked, and, as he points out, blockchain still wouldn't be able to track cash exchanges.
RE: Central Bank Issued Digital Currency Will Not Improve Monetary Policy