I do regret to have created a single bug, as I now realize that there are two issues that are less related than I first imagined. Is there a way to split a bug in two, so that both discussion can be discussed in different places.

Actually, after more search abound "unbound method", I discovered in https://www.python.org/download/releases/3.0/whatsnew/ that this concept was supposed to be gone for good in 3.0

The notion is also used in a few other places in the documentation but as far as I can tell the only "definition" would be in https://docs.python.org/3.11/c-api/method.html#method-objects. 
While my first suggestion here was clearly wrong, I believe it still indicates a documentation bug. In that if the concept is still in the language, "unbound" should be a link to this concept. If the concept is not in the language anymore, then it should not be used without explanation.
"super considered super" does not give a single example of super with a single argument. Which is probably great, because this case is far less super. However, this means that:
* there is currently no way for a user that want to discover python to know that there is virtually no more reason to use super with a single argument. 
* for someone reading a codebase with super called with a single argument, it would be hard to figure out what it does.

Actually, I was going to create a PR https://github.com/Arthur-Milchior/cpython/commit/dd453acad2b1f61867717cee4b47f944d37fb213 before seeing your answer, and while less certain, I still believe it has merits