DKIM, SPF, and DMARC are old hat and implemented by anyone serious for years. What's buried in this article is the required https://datatracker.ietf.org/doc/html/rfc8058 support for one-click unsubscribe posts. I don't see many messages in my inbox yet with that.
The article gets it wrong. They imply that emails have to have one-click unsubscribe links, which isn't true. Emails need to include headers (described in your link,) which the mail client can use.