Thread:Support/incubator messages/reply

zh-cn already falls back to zh-hans, and it has been this way for a long time. You're misrepresenting how localisation works: if a message at MediaWiki:somemessage/zh-cn is not defined, its page will not magically mirror MediaWiki:somemessage/zh-hans. Instead, when software requests that message to use in interface, it will end up receiving a zh-hans variant.