Google is giving you a way to get updates for its Home speaker before other people do. All you have to do is volunteer to be part of its Preview Program, which was originally launched for Chromecast in 2016. If you sign up for the initiative, your device will be one of the first to receive the latest features -- it's not for beta testing, so you don't have to worry about installing software that's not ready for public release and encountering bugs all the time. Still, Google is asking participants to send in their feedback about any issues or their experience as a whole whenever possible.
To sign up for the Preview Program, fire up the Google Home app on your phone and go to Devices to find your Home speaker. Tap the hamburger menu on the upper right corner of the device you want to enroll, click Settings then Preview Program. After that, you'll just have to choose to get email notifications to get pinged whenever you can download an update, and you're good. If the option isn't available for you, it's possible that all the slots are currently taken. Try another time in case Google opens up more.