This is just pairing the Echo as a Bluetooth speaker. We’ve always been able to do this.
The problem with this method, as opposed to native TTS, is that while the echo is paired as a Bluetooth speaker it can’t do anything else. So if you want to use it to send a voice notification to the teens in their room, no one else can use it during that time to turn lights on and off. Or ask it what’s on their calendar, or ask what the weather is, or anything else.
You have to unpair it as a speaker before it can go back to its usual state.
That will work for some households, but it’s not what most people are looking for with TTS.
edited to note that the description above is how Echo originally worked. As noted below, Echo Is now able to hear hone automation commands even when paired as a Bluetooth speaker. So a case where the features are ahead of the documentation. 