> If you are willing to sell, the interested buyer has no way to learn that short of a cold email to a WHOIS contact that privacy redaction has probably removed.

Has everybody forgotten about well-known email alias addresses? Inquiries about the hostname itself would be (among other things) exactly what `hostmaster@domain` was intended as a point-of-contact for. No need for a working WHOIS service, let alone a non-privacy-redacted WHOIS record.