I've noticed that the plural rules for Maltese (mt) in the current version of MediaWiki look wrong because they don't have a dual form. I consulted about it with a Maltese speaker, who confirmed that the current rules in MediaWiki are wrong, and the rules in upstream CLDR (version 46) are correct.

Updating the plural rules for all the languages should be a separate task because it may introduce various surprises and should be done carefully, so there should be a separate task for that. Until then, perhaps we can do something separate just for Maltese in plurals-mediawiki.xml.