Almost all services in that list are closed source, so even if they use end-to-end encryption nothing stops the client from sending all your messages to anyone they like after decrypting (in fact some of them already have it as a built-in feature in the form of backups).
Are you sure you don’t have some other software updating Firefox in the background?
Normally this only happens on Linux when your package manager updates Firefox while it’s running, and on Windows that doesn’t happen because Firefox updates itself only when you (re)start it.