There are 38 41 44 languages in getDefaultTermsLanguages() in WikibaseContentLanguages.php (recently added by @Mbch331) which were not also added to wmgExtraLanguageNames in InitialiseSettings.php.
This is needed to make them available for lexemes (see @Lucas_Werkmeister_WMDE's comment at T260118#6474757) and to make them sort correctly on Special:NewItem (see T272346).
See also: T273627: Remove wmgExtraLanguageNames from Wikimedia production