MediaWiki core wraps this message into parentheses by default which does not make sense for at least German. So please remove them. If parentheses are needed a language may wrap individually. Thanks and Cheers.
The gerrit change was abandoned, so if this is still relevant we'll need it filed on Phabricator...
Yeah, this is still absolute nonsense and every time I access my settings I start to loose faith again. In other words: Thanks for notifying. I will file a task.
Ok. I suspect you meant MediaWiki:Gender-unknown/en though. I think the parentheses are there to convey the fact that it's a non-choice, the default choice, or not a direct answer to the question above the radio buttons. Then I don't know how consistent this is with the other preferences etc.