I would also like to suggest to add "obsoleted" as a new "unofficial" status of a SRFI. On the home page srfi.schemers.org, we can then have a list of "obsoleted" final SRFIs together with their replacement SRFIs.
The old list of final SRFIs actually had this concept (for example, SRFI 40 was marked as obsoleted by SRFI 41), because it was maintained by hand. The new and presumably database-driven pages don't have a field for "obsoleted-by", though they should.