Oh comon. As if the the fact that intelligence agency could possibly use a preinstalled microphone of an electronic device, is in any way non-obvious or as if it's problematic that the 'intended' knows about this.
Truth is that all terrorists so far used unencrypted normal SMS services and burner phones, or the unencrypted chat services of various Playstation games. What, you want to make it a secret that intelligence agencies can see the chatlogs of Playstation games, too?
Mister obvious is obvious. A microphone in a smartTV can obviously be turned against the owner of the smartTV. Nothing special or secret about that. The news here is just the fact that with this it got confirmed that intel-agencies are doing this actively. Not that they can. They can from day one, even from before TV-sets came with microphones.