And it should be made clear that Telegram was forced into this position by the SEC who torpedoed any chance Telegram had of building out a decentralized network (TON).
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...