I logged into my UVI account today to check what Falcon expansions I had and noticed that a bunch of the UVI soundbanks I've bought have been updated (several times even), without any announcements.
Nothing seems to have been updated very recently (for me), but I ended up re-downloading all of Vintage Vault 1 -- since every single thing had been updated since I last downloaded. One interesting change was the size of Xtreme FX, it basically halved from 9gigs to 4.5gigs (better compression I suspect).
If you login to your account you can see the current version of soundbanks and download them. Inside the UVI player if you select a soundbank, at the bottom of the info panel(scroll down) you can see what version you currently have. They do have change notes on the website, though they seem a bit lacking in details, most of the releases list only "minor fixes". Pretty much everything I have bought had an update.
If you have a few UVI soundbanks you might want to login and check.
https://www.uvi.net