Surprisingly enough the default organisation/environment language is not used when configuring new Knowledge Articles. Instead "English - United States" is selected by default. The product team should strongly consider changing that behaviour so it matches the default language set at the organisation level or provide a configuration setting to allow customers defining their preferred default language for Knowledge Articles. Changing that attribute each time someone is creating a new KB record is annoying and time consuming. Typically KB administrators forget about it so they need to manually translate each KB record to their preferred/required language after the fact which is even less enjoyable.