Apparently the new brand for speakers and displays with Google Assistant is now "Nest" -- as far as I can tell the Nest Mini and Nest Hub are the same hardware (?) as the Google Home Mini and the Google Home Hub. (And the "Nest Audio" is the new version of what was the original "Google Home".)
If you view the “Nest” brand as a thermostat brand, it doesn’t make sense. But if you view it as a “smart home” brand, it makes sense. However, rebranding to a different product name never makes much sense. It just confuses the public.