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:

WhatsApp is introducing a new chat memory feature for its Meta AI chatbot currently available to select beta testers who can access it in the latest WhatsApp beta for Android 2.25.11.13

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