I expect that they don't lie on their public website. This is what WhatsApp says on their own website https://faq.whatsapp.com/general/security-and-privacy/answ

I expect that they don't lie on their public website. This is what WhatsApp says on their own website https://faq.whatsapp.com/general/security-and-privacy/answering-your-questions-about-whatsapps-privacy-policy/?lang=en https://faq.whatsapp.com/general/security-and-privacy/answer... : Neither WhatsApp nor Facebook can read your messages or hear your calls with your friends, family, and co-workers on WhatsApp. Whatever you share, it stays between you. That’s because your personal messages are protected by end-to-end encryption. We will never weaken this security and we clearly label each chat so you know our commitment.