Let's say I'm the NY Times and I host a page on my server at nytimes/2020/01/22/some-article. 1 hour later I realize I got one of the facts wrong, so I modify that hosted page on my server.

I'm not making HTTP requests here, but, to your point, I am mutating the document at that url.

Maybe the protocol would somehow store the diff between those 2 documents somewhere. There could be an organization, similarly structured to ICANN, that stored and surfaced those diffs long term to users.