For that 3 GB? (Assassin's Creed: Revelations)
Today(14.07.17) I went into steam and saw the update to 3 GB.For what reason?
brotherhood's update did add free dlc that was previouslt ony available to the PS3. check it out here: http://assassinscreed.wikia.com/wiki/Copernicus_Conspiracy
as I understood from the discussion of steam added DLC Copernicus Conspiracy
And in AC:BH and AK2 was trehshovnye patches that adds Chinese language only and all. In principle, it is possible to download from steam and see what they added.
A glimpse so looked to compare a couple of files inside, all the same, added only the following files: LocalizationPackage_Chinese(Trad), LocalizationPackage_Chinese(Trad)_Subtitles, LocalizationPackage_Chinese(Trad)_EManual, LocalizationPackage_Chinese(Simp), LocalizationPackage_Chinese(Simp)_Subtitles, LocalizationPackage_Chinese(Simp)_EManual. All the files that are too lazy to check, maybe some DLS now work without the abandoned. In the game and the story, I think, no change there.