FAQ 5.2 still correct?

Hi!

Gnus FAQ 5.2 [http://gnus.org/manual/gnus_367.html#SEC418]
tells me to use

     (setq message-required-mail-headers
          (remove' Message-ID message-required-mail-headers))

to avoid gnus setting my Message-Id in emails.
Is this still valid? google groups shows nothing using this or
this (setq message-required-news-headers)
search for about 4 (!) years.

Leafnode sets my News FQDN correctly for me (using hostname= option).
But my emails still show my (invalid) hostname like
      <831w2n7t9g.fsf <at> hostname.RP614v4>

Could someone please confirm it still works?
If so, what could override this setting?

Thanks a lot for your help.
I really appreciate it.