Comment # 28 on bug 1222429 from David Sterba

Nothing happend, it stands and everybody is perfectly aware of that, thanks for
asking. Any change that could affect userspace is first announced, deprecation
period set and if nobody responds then the option in this case is removed, with
a substitute for the functionality.

The deprectaion was announced in 5.11, since commit fed8f166ebf3afb a warning
is printed in system log. We can't do more, if users or application developers
ignore or do not notice such things it's not breaking userspace from us.
Deprecation period lasted 3 years (5.11 to 6.8), we can of course make it
longer and we do that for other features. You can simply ask for extending it
if eg. systemd wants to guarantee some sort of LTS support, but otherwise we
remove the things as announced so we don't drag too much deprecated code along.