periodic(8) pkg_* tasks not in /etc/defaults/periodic.conf ?

I usually start with /etc/defaults/periodic.conf for candidates I might
want for customizing periodic(8) behavior.  I also check the various
periodic man pages, and scripts themselves occasionally.

Recently I checked periodic.conf(5) and found there are some documented
variables which do not also appear in /etc/defaults/periodic.conf e.g.:

    weekly_status_pkg_enable

as well as pkg_version and pkg_version_index, possibly others.

It seems like most of the man page variables have default settings in
/etc/defaults/periodic.conf so maybe the missing pkg_* variable(s)
entries are a simple omission?

Adding weekly_status_pkg_enable="YES" to /etc/periodic.conf[.local]
works as expected, it just seems atypical there's no default for it.

Happy to file a bug if that's appropriate.

Cheers,
sr.