An interesting changelog entry for those of you upgrading a fully disk encrypted Debian Bookworm box to Trixie:
Changes are required to /etc/crypttab, or the encrypted disk will become unreadable, appearing as random data. The changes should be made before reboot post dist-upgrade, as an encrypted '/' will include the above file!
(Edited to remove LUKS reference as does not apply to partitions of this type - thankyou @spnl )