For those of you who use your Assistant-equipped Smart Displays and speakers to broadcast music around different rooms of the house at the same time, Google has made a small improvement. Devices and cast targets can now be added and removed on the fly without creating new groups, which should make things a little more convenient for some.
Google has made small improvements to multi-room audio as time has gone by, including individual speaker volume control and the ability to change a cast target or cast to an already created group. This latest update, however, allows you to "dynamically group multiple cast-enabled Nest devices (speakers, Smart Displays, Chromecasts) in real-time to fill multiple rooms with music." What this means is that you no longer need to pre-create groups to determine which devices/rooms the audio will be sent to; instead, you can simply choose which devices you want to have audio played from whenever you'd like.
This new feature will be accessible from the bottom left corner of your Smart Display's screen when audio is playing. It'll work with many audio apps — Google specifically mentions YouTube Music, Spotify, and Pandora. It's rolling out to all Nest Hub, Nest Hub Max, and other Assistant-equipped Smart Displays today, and will roll out to the Google Home app in the fall.