Before English in the fallback sequence for the Atikamekw language (atj), it should be French (fr) as the main language of Atikamekw people (after Atikamekw itself of course) is French. All the Atikamekw population also speak French, but not all speak English. Thanks.
Makes sense, thanks; but this language is only on translatewiki.net so far (not exported because less than 100 messages were translated). The language fallback will be added to MediaWiki as well when the language is added.