MDN has never been "authoritative reference documents". It's a wiki. Anybody can edit and republish pages, change examples, do whatever. I noticed somewhere about a year ago that it was a wiki, and have made minor changes to a couple of pages since then, when something was missing an example or something.
I change, I publish, it's done. And if my change was wrong, or opinionated, or bad, it's just like that until somebody else catches it and fixes it back.
Neither Safari, Chrome/Chromium, IE, old Edge, nor new Edge have substantial HTML and CSS developer documentation on their own web sites. Their vendors - excepting Apple and the WebKit contributors - all chose to work with Mozilla instead to put their docs on MDN: https://blogs.windows.com/msedgedev/2017/10/18/documenting-w...
It seems to me that as far as the browser makers are concerned, MDN is as close to authoritative as you can get without going to the standards documents themselves - and the standards don't give you browser compatibility matrices or make any note of browser-specific quirks.
MDN may be a wiki, but it certainly isn't treated like one by the people who are most interested in it being accurate and up to date.
"Authoritative reference documents of MDN are going to become cluttered with comments and disagreements"
Which suggests previously authoritative docs are becoming less so due to being editable. I'm just pointing out they are and always have been subject to edits from the public. If anything the PR process will likely increase the reliability of the info because there would be a chance to do some vetting of changes.
I totally agree that MDN is as close to authoritative as you can get, but it's one (important) step away.
I think people put authoritative sources on too much of a pedestal because it's possible for someone to naively or maliciously edit wikis. People who write official docs are also frequently wrong, and the editing and review cycle there is far slower!
Every recent review I've seen of Wikipedia vs arbitrary big-a Authoritative sources has said that both have issues and overall Wikipedia is better.
I change, I publish, it's done. And if my change was wrong, or opinionated, or bad, it's just like that until somebody else catches it and fixes it back.