Meta said in a blog post that its Advanced Chat Privacy is a toggle setting that opts chats out of AI features and also keeps chats from being downloadable or from making media auto-downloadable to devices. The blog post does not specifically mention Meta AI. The blog post reads in part:

Popular messaging app, WhatsApp is setting up its privacy game with a new feature called Advanced Chat Privacy. This has been designed for both individual and group chats. This setting adds an extra layer of protection to keep your conversations more secure and private,

WhatsApp has introduced Advanced Chat Privacy, a setting that helps keep content, such as photos and sensitive chats, from spreading outside.