I think they’re just referring to an outdated concept of OSes with non-journaling filesystems that can cause data corruption if the disk is shut off abruptly, which in theory could corrupt the entire disk at once if it was encrypted at a device level. But FDE was never used in the time of such filesystems anyways.
Define properly shut down. Do your thieves usually ask first?
I think they’re just referring to an outdated concept of OSes with non-journaling filesystems that can cause data corruption if the disk is shut off abruptly, which in theory could corrupt the entire disk at once if it was encrypted at a device level. But FDE was never used in the time of such filesystems anyways.