You’ll soon have no choice but to let WhatsApp share your data with company parent Facebook if you’d like to keep using the service.
If you don’t agree, the same alert subtly suggests you delete your account.
However, the opt-out came with a condition: you had to activate it within the first 30 days of signing up with the service. (Even if you did, WhatsApp could still share your account data with Facebook for the purposes of “operating and providing” the messaging service.)
However, messages sent over the app will remain end-to-end encrypted, meaning neither WhatsApp nor Facebook can read them.Source