[omgomgomgomg]

They can decrypt if someone enables backups, so I see no reason they could not read them indeed.

Signal might be the only app unable to read, but even that, I would not trust.

[marcus0x62]

How would you propose Signal -- or any app for that matter that provides end to end encryption -- encrypt the messages in the first place if they don't have access to the plaintext at some point?