I would have preferred a selective unpinning by some rule that
takes into account the difference in the number of votes between
the accepted and the most upvoted answer.
Sometimes one can come upon an accepted answer with one upvote,
with another answer having several dozens of upvotes.
Clearly in such a case the accepted answer is not generally accepted,
"There is no way you can do this because..." is a valid answer. If you are starting from a potentially faulty assumption then having someone explain that fault and what, if anything, you can or cannot do about it then that is still an answer even if it does not provide the "solution" that you wanted.
Someone might come along in the future ...
I'm actually kind of leaning towards keeping the status quo.
We don't have the volume of SO, and many of our questions are narrowly scoped enough that if an answer's outdated, so's the question (and someone can ask a question about a new version and refer to the old one if needed).
I also feel that unpinning the selected answer might be more not less ...
I can see a tag synonym from [variable] to [variables] but no questions on either tag. If there is a synonym then the tag existed but it is entirely possible that it was emptied out as it is a meta tag (requires other tags to describe it) and it is not really relevant to this site.
It is possible that the synonym is holding a block on the proper deletion or ...