My iPhone is on v2 of Public Beta 16.2 as are the HomePod Minis and Apple TVs in the house, but not the HomePods or the other iPhones. I see the screen asking me to update the Home but I think it's failing because there is not a public beta for the original HomePods. Just wondering, is the interface any different?
I updated my HomePods to the beta. It is available to the public.
The only reason I did this, though, was because my automations were so poor on the previous version, hence I was willing ton update all my devices. Literally everything is on a beta at the moment (iPhone, Apple Watch, MacBook Air, iPad, Apple TV 4K, all my HomePods.)
Just by way of an update, updating to the new home architecture did not improve all aspects of the home. The automations were still hit and miss, particularly the location-based ones, and we also experienced some automations triggering when they shouldn't. We were sat watching TV when our hallway light came on (it's supposed to do that if either of us are arriving home, but we were already there) and then, 10 seconds later, the entire home shut down (another location-based automation, for when we leave the house, but we were both there... Watching TV.)
I decided to recreate all the scenes and automations in the new home architecture, just in case there were any issues hanging over from the previous version. Since doing so, all the automations seem to work.
I'm continuing to test.