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

We think this feature is best used when talking with groups where you may not know everyone closely but are nevertheless sensitive in nature,” the company added.