pkg-rquery(8) does not show messages of packages

I'd like to view the package message of a package which is not installed on my system (an equivalent of pkg info -D firefox for remote packages). I've tried to use pkg rquery -e "%n = firefox" %M for that but I just get an empty line instead:

$ pkg rquery -e "%n = firefox" %M

I am not sure but it seems to be a bug as other query patterns work just fine, e.g.:

$ pkg rquery -e "%n = firefox" %o
www/firefox

In 2019, reportedly not a bug.

Re: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=230770#c3, repository metadata does not include package messages.

@bapt wrote:

… rquery should not allow %M