I don't think it'll be known. I bet what you described already happens and yet it attracts far less attention than the end to end encryption shenanigans.

I also think WhatsApp messages backup is literally a backdoor to bypass the end to end encryption.

I think government RCE is far more serious concern than encryption, yet it gets no attention.

We hear about the encryption from all the second class governments that are blocked from the juicy NSA backdoors of auto updates. Ever noticed how the NSA stays quiet in all those encryption debates?