The 2GB patch supposedly only adds Korean, Simplified Chinese, and traditional Chinese to the game. Some people are reporting patches up to 3.9GB in size. Steam players are reporting their save games are broken.
I just patched through Ubisoft's UPlay application and received a patch of 460 MBs. My save games work. I don't have the season pass DLC and did not buy the game through Steam.
"I used to think the worst thing in life was to be all alone. It's not. The worst thing in life is to end up with people who make you feel all alone." Robin Williams