I find the wordsmithery on Meta's statement the most interesting: “We do not track your *PRECISE* location, we don’t keep logs of who everyone is messaging and we do not track the *PERSONAL* messages people are sending one another," it added. “We do not provide *BULK* information to any government.”
Aren't push notifications logged and used for getting people's data? This was in the news over a year ago: https://www.wired.com/story/apple-google-push-notification-s...
On Android, push notifications were always processed by the receiving app, so it can just decrypt a payload directly (or download new messages from the server and decrypt these); on iOS, this isn't as reliable (e.g. swiping the app out of the app switcher used to break it in several iOS versions), but "VoIP notifications" and the newer "message decryption extension" [1] are.
The same principle applies to Web Push – I believe end-to-end encryption is even mandatory there.
[1] https://developer.apple.com/documentation/usernotifications/...