There are many privacy-preserving technologies that are used by existing blockchains.

Some examples of privacy-preserving blockchains, each using different technology: Monero, Grin and Aztec.

The loudest critics of CBDCs point to the surveillance aspect of CBDCs. But that doesn't necessarily need to be the case with a privacy-preserving blockchain.

Will any country announce that they intend to launch a blockchain CBDC that uses some form strong privacy-preserving technology?