https://wccftech.com/download-watchos-8-4-final-for-apple-watch-now-available/

watchOS 8.4 final update for Apple Watch Series 7, 6, 5, 4 and 3 is now available to download over the air. This is a bug fix release.

Apple claims that this is a bug fix release and is important that every user with a compatible Apple Watch go ahead and download it immediately. Who are we to argue with that, right? So, here's what you need to do in order to download watchOS 8.4 update onto your Apple Watch right now.