Last modified: 2013-04-22 16:14:42 UTC
The "untranslated" filter is not currently available in the page view. Since this view is suited for translation (especially for translatable pages) it make sense to have a view for the messages that can be translated. This is a different case than the proofreading view (where it makes no sense to show untranslated messages that cannot be proofread).
Patch: https://gerrit.wikimedia.org/r/#/c/54213/