I believe this policy is probably related to another policy called “Biographies of Living Persons” - where material about living people (especially if said material is negative about the subject) must be reliably sourced in order to be included in articles. As its founder once said,
Real people are involved, and they can be hurt by your words. We are not tabloid journalism, we are an encyclopedia.
I’m not sure that analogy works here since tabloid journalism is heavily influenced by its subjects (and their publicists) whereas an encyclopedia is supposed to exclude their biased perspective.
The policy of reporting a birth name, only using that name if the subject was widely known under it (and then, only as little as possible consistent with the style guide, e.g., not overusing an old first name), and relaying the circumstances of a name change is fine.
Poll
