"In general, no matter what features you use, WhatsApp cannot read your messages due to a technology called “end-to-end encryption”, or E2EE. Knowles described it as acting like the message is locked. “Your messages are locked, or encrypted, on your phone and only unlocked, or decrypted, when they reach the person you’re talking to,” she said.
Importantly, only the sender and intended recipient of a message can unlock it. This means that even WhatsApp itself cannot read the content of messages.
However, while E2EE protects the contents of your messages, calls and files on WhatsApp, this protection doesn’t cover all the data created when you use the app.
Thorin Klosowski, a security and privacy activist at the Electronic Frontier Foundation (or EFF) told Africa Check: “In the case of WhatsApp, the company collects metadata, such as when a message is sent, who the messages are between, and where it is sent from.”
Metadata is information about a particular piece of data. For example, if the data is a text message, its metadata might include the time it was sent or the place it was sent from.
Although the contents of a message are protected by E2EE, it is impossible to protect a lot of metadata. WhatsApp will, for example, always be able to determine the time a message was sent and the recipient."
https://africacheck.org/fact-checks/blog/viral-whatsapp-warning-wrong-app-does-have-privacy-concerns
