Why the surprise?
Meta has access to the folder it manages in the user's Google Drive. That's obvious, otherwise they wouldn't be able to write to it.
They have indirect control over the user’s backup folder via the app, but meta would need to distribute a malicious update to everyone that causes the user’s apps to download the backup and send it to meta, at which point they could just skip trying to access the backup and directly upload the chats from the app.
It’s impressive how much misinfo you’re spreading.
Edit: Meta’s actions over the years clearly show that they don’t want to know the contents of your messages. Not knowing their contents means, for example, that they don’t have to run scanners to detect illegal content (but users can report messages). They benefit from making WhatsApp a secure platform, as it allows them to collect everyone’s metadata, which apparently has lots of value to them.
Haha. That's a great proof! Not the closed source, not the proprietary protocol they use to talk with their server, but their FAQ.
> They have indirect control over the user’s backup folder via the app, but meta would need to distribute a malicious update to everyone
Please give us the results of your research when you reverse-engineered Meta's apk to prove your point as this is what you think others should do. Otherwise it is just big talk.