Ubisoft has been hard at work to make sure Rainbow Six: Siege has a long lifespan, including Operation Health to improve matchmaking (they have said it's "here to stay" after all), and the latest update is going to be a part of this, as explained on the game's official website.
From the offset Ubisoft makes clear that this patch will be larger than usual, and in it they'll be making changes to how data is organised and how they generat patches in the future. What's caught our eye, though, is the size of the patches (which are subject to change), as PC with Ultra HD can expect a whopping 42GB update, whereas without Ultra HD it's reduced to 26GB. PS4 and Xbox One users, however, only have to download 15GB.
This new Y2S3.0 patch will be the baseline that they will update the client from in the future, which means replacing a lot of existing data forges, hence the size. The compression algorithm in the game is also being updated, but check out the full post if you want more detail on this and the data forges.
Do you mind big updates?