My mediawiki interface language on ARWP is set to Hebrew, for convenience. I am based in the US. Today, I saw a CentralNotice banner activated on HEWP (and definitely not on ARWP) show up above an article on ARWP. Changing my interface language on ARWP to English made it go away. Changing it back to Hebrew made it come back (over articles, not the main page).
I attach a screenshot.
(Presumably, the interface-language somehow carries with it something that satisfies the test "is this Hebrew Wikipedia?" as far as CentralNotice is concerned.)