https://wccftech.com/massive-cod-modern-warfare-warzone-season-4-patch-notes/

Call of Duty Modern Warfare and Warzone Season 4 patch is being rolled out across all platforms and we’ve got you covered with the full release notes.

Activision and Infinity Ward already announced that the Season 4 update will be rather huge due to the team trying to reduce the game’s overall file size. As such, various assets are being compressed, allowing for the latest update to require only 4GB of additional space on both PS4 and Xbox One, once installed.