ISOC/IAB/IESG/IETF/IANA/whatever is blatantly violating these rules when
it gives authority to someone like Keith to declare that, for example,
Mail-Followup-To shouldn't be implemented.
I can't imagine that I'd be asked to do the expert review for
message headers. Even if I were asked, I wouldn't accept.
So if that's what you're worried about, you can relax now.
Keith