Please provide clear info in relevant release notices and (later?) user manual.
Automatic random GUI password confuses locked-out users who never set it,
however at least that can probably migrate to new system. Unsure of this one.
EDIT 1:
I’d guess migration between accounts on the same system is also a use case.
EDIT 2:
Also OS reinstall on the same system from an image backup or vendor media.
The downside of any automatic encryption is if a legitimate use case is denied.