Because who doesn't like an update that makes the game harder! ;)
There are many various updates to many systems to the game, the main update being an AI overhaul to aggressive animals!
Many animals are faster and smarter. And you can no longer "cheese" kill aggressive animals (sorry Kastuk)!
Also, there are many updates to performance issues and lighting, you can read those in the patch notes.
https://steamcommunity.com/app/342910/discussions/0/3130541756145911806/
Enjoy!
Changed files in this update