Remember this is the same company that just gave police DMs that aided in an abortion investigation. If those had been end to end encrypted that risk would not have existed, but they made a business decision to leave the application vulnerable to spying for profit reasons. That is a vulnerability, in the same way we call it a vulnerability when an entity man-in-the-middles a browser to spy on people.

Personal user browsing or communications leaking in plain text to private companies without explicit and obvious user consent puts users at risk, and is a vulnerability. It just so happens to be one arising from malicious profit seeking behavior that happens to be the status quo.

Not having https was once the status quo, and a boon for corporate spying, but we call that a vulnerability now because the abuses became too big too ignore.