TPM DUK vs Disk Recovery Key passphrase still unclear for users

Asked user to clarify what is unclear in official docs at https://matrix.to/#/!DuZPJBBoKAZyvrWmpv:matrix.org/$lvvnnBLUTT4zyZjNSCXeFe3q7SAlhszrCk6Fw6ds0OA?via=matrix.org&via=nitro.chat&via=tchncs.de