It's commonly misquoted that WhatsApp data will be shared with Facebook, but the Signal protocol for WhatsApp personal chats remains as is. It's the WhatsApp user-business communication that will be visible on third-party interfaces, like Facebook. It's in this process the e2ee aspect of the chat is lost. [1]

Overall, WhatsApp still remains a safe platform for 1:1 communications and group chats, but there are still many other factors that could be sold by Facebook, including location data, contact info, online status, and other aspects of the platform.

Durov did announce plans to offer more features for premium customers. [2] Hopefully that will help offset their hosting/development costs, without them succumbing to data selling practices.

[1] https://gizmodo.com/this-was-whatsapps-plan-all-along-184606...

[2] https://t.me/durov/142

Which is why you should look at what Telegram has actually done and that has been to protect and preserve the privacy of its users since the beginning.