The Amazon Echo uses its Alexa assistant software to help it talk to a whole bunch of things. From the interconnected lights to the interconnected thermostat in your home to the Amazon warehouses, it needs some language to talk about turning them on and off and it needs some range to reach those things.
The Information is reporting that the assistant hub will actually be comprised of a speaker, microphone, LEDs and the guts of a Chromecast. Hey, if a Chromecast can run web interfaces, games and a ton of media on its own, imagine what it can do with the right Wi-Fi antennas talking to IoT devices on the Google Cast protocol.
All this becomes less about Google Home being one-upped Chromecast and more about good programming, good base hardware and a little ingenuity to save the effort of sourcing new components.
Who wants a serving of Raspberry Pi?