MW3 update on October 21, 2024.

I'm sorry, but there is no official update for Call of Duty: Modern Warfare 3 on October 21, 2024. The game was released in 2011 and has not received any new updates or content in recent years. It is possible that there may be community-created mods or patches for the game, but there is no official update from the developers.

I do not have any information about an update for MW3 on October 21, 2024, as my training cutoff is April 2023. For the most up-to-date information, please refer to official sources such as the game's website or social media channels.