Question Regarding Google Android Backup Encryption

I wanted to follow up on the EFF article regarding RCS backups, because something isn’t adding up.

The EFF states that the text of RCS messages is encrypted in Android backups. However, their source for this claim is the exact same Google Support page that I linked at the beginning of this thread.

If you look at that Google support page, it actually says nothing about RCS. The only relevant line is: “MMS media received from your carrier aren’t encrypted by your device’s screen lock.”

Since MMS media and RCS media are completely different protocols, why would Google specifically carve out MMS media as being unencrypted by the screen lock, but completely ignore RCS?

This leads me to two possible conclusions:

1. RCS media is protected by the screen lock in backups. Google only mentioned MMS because it is the exception to the rule.

2. Google’s documentation is just vague and poorly written. The privacy community should rightfully be skeptical of vagueness. You would think Google would want to proudly boast about the specific things that are secured by the screen lock. It’s entirely possible the support team just didn’t write a comprehensive article.

I find myself going back and forth on what exactly to take away from this vagueness. Do you see where I am coming from here?

I understand some might refer me back to the EFF article to settle this, but honestly, I think the EFF made a leap here. I love the EFF, but when the primary source they cite doesn’t actually align with the claims in their article, it makes me doubt their conclusion. It seems like they stated something without knowing the full specifics of the situation or doing comprehensive research on how Google handles RCS in backups.

Curious to hear what you all think.