Danil,
You piqued my curiosity, and I've run a test (since we maintain RFC 8058 implementation at Mailman3.com) to see how Gmail treats messages from a mailing list with regular Mailman headers vs. RFC 8058 headers.
Are you saying I should see RFC 8058 headers on this list? (mailman-users@mailman3.org) If so, I am not...
On the other hand, Yahoo (I know that friends don't let friends use it) offers an unsubscribe option even without the RFC 8058 headers, and it sends a valid unsubscribe request by email to the mailing list "leave" address when you click it.
Yes, I've noticed Yahoo and others do some automation with the RFC 2369 ("List-Unsubscribe") headers. It looks to be like Google does require "List-Unsubscribe-Post" headers, which require List-Unsubscribe include an HTTPS (and not just a MAILTO) URI.
Regards, --Jered