- Send a message to someone whose phone is off

- turn off your phone

- get that person to turn their phone on

- they receive the message.

Where was it stored, if not in WhatsApps servers?

Well, not exactly what I meant.

Burn your phone, setup a new phone, log in, view your messages was what I meant.

Whatsapp backs up unencrypted messages to Google cloud on Android and whatever it's called for Apple.

The government can just ask them to turn over those. (note that this is legally very different from forcing someone to unlock a device)

It does not just do that, no.

It has the option of doing that, it asks you if you want to enable the backups. It also allows you to encrypt the backups with a passkey or a password that you can manually set, client-side.

It didn’t always have the encryption option I think.