I remember reading an article where the government and Google were able to read notifications and record them from every android device. I wonder if Graphene might have patched this problem, and if not, do they have any plans to do so?
Firebase is a platform/service provided by Google, so it makes sense that the content goes thru Google's servers.
Also, E2EE in a closed-source app like WhatsApp, run by a nefarious corporation like Meta, was always a joke concept, a marketing ploy at best. People who are truly concerned about their privacy would never touch WhatsApp.