Call of Duty: Black Ops 4 has been updated to version 1.16 by Treyarch. This implements some security and bug fixes as seen in the patch notes.
The file size is just under 500 MB for this update and it appears to relate to the launch of Black Ops Cold War. There are currently no official patch notes or details shared on this update. Just like Black Ops Cold War, this one has been released recently in order to keep the in-game server stability up-to-date which is a norm for every past Call of Duty game.
Call of Duty: Black Ops 4 Patch Notes
- Security and stability fixes.