Meta/WhatsApp could be weasel-wording here, where they technically do have "end to end encryption"... but also a process which bypasses it.

That might mean access to the automatic chat-backups which by default are not end-to-end encrypted (so that Archetypal Aunt Tillie can get her chats back when her phone is lost) or some mechanism that controls the client-program.

By default, WhatsApp chats are backed up to Google (Apple?) storage in an unencrypted form.

I think it matters how you define 'end-to-end'. Where are the endpoints? In a SaaS platform, WhatsApp could claim your device and its ingress server are the endpoints. With that definition, they can use TLS and claim E2EE.

But some people would expect the two endpoints to be their device and their human counterpart's device. Mobile app to mobile app and encrypted across all servers.