Here is a comprehensive review covering the film's arrival, its technical "dual audio" features, and the downloading/viewing experience. The Arrival: A Modern Sci-Fi Masterpiece
Thus, many "UPD" files you find are actually re-uploads of 2017-2018 rips, not genuine new releases.
When looking for the latest "upd" (update) for a movie file, enthusiasts are usually looking for improvements in compression and clarity. Over time, newer encodes become available that offer better visuals with smaller file sizes.
Subreddits like r/MovieRequests or forums like Snahp.it (if still active). Do not ask in public comments on mainstream sites.