IMHO syndicated (category) blocks (like .rss feeds in blocks in WordPress) need not to have separate rendered page, let alone items in any other wiki, but just display as links to here.
Technical work I can imagine should be on generating RSS with all topics in all languages and checking if that works well enough *(+ having fallback that .rss displays also in EN which should be checked also by fellow humans :-p )…no? Categories of different types of announcements need most care *(and editorial overview), but if the block view is not enough than some custom work needs to be done beyond just rendering titles.