Depends on the implementation. Many organizations are just using blockchains for a standardized namespace for pseudonyms and standardized toolkit for non-chain

Depends on the implementation. Many organizations are just using blockchains for a standardized namespace for pseudonyms and standardized toolkit for non-chain encryption. So the users in this case would just sign a message for uniqueness, instead of relying on other forms of entropy like their phone or something. They wouldnt be writing anything to a blockchain for tracking and the addresses wouldnt be used by anything else or have funds in them. There’s no reason the Luca app also couldn't do it this way. But I’m not sure if it would have mattered, or why the health department had identifying data after decrypting anything.