The article makes it unclear, but this feature is available right now for all Nest Aware subscribers (if you have any type of Nest camera, you'll have a Nest Aware subscription). The article mentioned that this feature was "accidentally" available to non-Nest Aware subscribers as well, but it's the same existing feature and not some test of upcoming features.
You can toggle glass break and fire alarm detection on any of your Google Home devices in the Home app, and this includes the old Google Home mini pucks and hubs, as well as new Nest branded minis and hubs.
Nest cameras are a completely different system than Echo, all Nest camera devices stream full motion video and audio back to Google 24x7. That's why you buy them.
You can toggle glass break and fire alarm detection on any of your Google Home devices in the Home app, and this includes the old Google Home mini pucks and hubs, as well as new Nest branded minis and hubs.