The statement “This update does not expand our ability to share data with Facebook.” seems to be perhaps carefully worded based on a technicality that they, WhatsApp, are not the ones sharing the business conversations with Facebook, but instead Facebook is giving the businesses themselves tools to share them with FB for ad targeting.

From earlier FB announcement (https://about.fb.com/news/2020/10/privacy-matters-whatsapp-b...): “When Facebook acts as a hosting provider to a business, it will use the messages it processes on behalf of and at the instruction of the business. This is an industry standard practice among many companies that offer hosting solutions. While Facebook will not automatically use messages to inform the ads that a user sees, as is always the case, businesses will be able to use chats they receive for their own marketing purposes, which may include advertising on Facebook.”