WhatsApp will be sharing information like, “the phone number you verified when you registered with WhatsApp” and “the last time you used our service”.
WhatsApp promises on their newly updated FAQ page that nothing we share on WhatsApp, such as messages, photos and account information will be shared with Facebook or any of the Facebook family of companies. And according to what we know about the end-to-end encryption WhatsApp is now renowned for, nobody except you or the person you are talking to should be able to see what you are sharing. Even the information that you are sharing with Facebook, will not be visible to everyone.
But even after all this, if you are uncomfortable with this sharing of information you have the choice to turn it off.
To do that, you will need to
1. Open WhatsApp.
2. Tap Settings.
3. Select Account.
4. Tap “Share my account info”.
5. Tap “ Don’t share.”
A slight pop up tells you that the decision cannot be changed in the future. And after that the whole option disappears.
For users who do not have a Facebook account, just keep using WhatsApp as you have been doing. No changes for you.