I think explaining decisions which might not be obvious to a person who
was not around when the decision was made is a good thing.
Why isn't the IETF mailing list archive discussion about the status change
sufficient as an archival record?
More than that, actually: the current process has added a
pseudo-document that we use to manage the status-change process:
https://datatracker.ietf.org/doc/status-change-adsp-rfc5617-to-historic/
That pseudo-document has the necessary information, but it not
published as an RFC. I think that if the RFC metadata were modified
to point to the status-change document, so it's easy to find when one
is looking at the RFC, that should be all we need.
Barry