I've been using emacs as my MUA for years.

When I upgraded from emacs 26.3 to emacs 27.1, i noticed that
message-forward-as-mime now defaults to nil.  I prefer to forward as
MIME generally, so i set it back to t.

The only downside to forwarding as MIME is the inclusion of some headers
that the received message has accumulated in transit, which might have
privacy-sensitive implications. I've been using
message-forward-ignored-headers for a while now to trim out headers like
Received and Delivered-To when forwarding.

But as of 27.1, message-forward-ignored-headers doesn't work when
forwarding as MIME.  indeed, the help text for the variable now says

 >> This variable is only consulted when forwarding "normally", not when
 >> forwarding as MIME or the like.

But this is a regression from 26.3.  I'd expect it to keep working.

Please restore the functionality so that i can automatically strip
privacy-sensitive headers when forwarding.

Thanks,

     --dkg