As far as I understand this, correct me if this is wrong, this means the content of your messages is encrypted. There is still important data to fetch about who you talk to, how much and when.
I don't know why you're downvoted because that's exactly the point: the creators of closed-source applications may claim whatever they want, but you have no way of verifying their claims. Especially if the owner is the company whose income is based on profiling you, and the fight over FB<->WhatsApp profile linking is no longer a secret now.
