I have not found any news article on this on a whim. Because my friends and family, I need to use Facebook Messenger, and Messenger Lite was a OK client - lightweight, no unnecessary features, etc., compared to the regular Messenger app.
Now I'm a little torn, having a Meta app on my phone is already bad, but having to downgrade to the bloated Messenger app? Not sure I will make a change. What are your thoughts?
No. Due to how whatsapp works, you have to have a phone with whatsapp installed, somewhere.
The matrix bridge connects to that, and "puppets" your account, bringin those chats into your matrix account.
Matrix can bridge to a ton of different chat services, but each one can work a little differently. They usually don't support voice and video.
Matrix is what's behind the scenes for beeper, for example.