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

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.