If you had any HomePods you couldn't disable them. So they could take over at any time, and you had no control. Even when AppleTV allowed you to disable it, HomePods have never had that option.
And technically, even then, you had no way to set a preferred hub you could just disable it on any AppleTV's you didn't want to BE a hub. But that also meant they wouldn't take over in the case of the main hub going offline for whatever reason, so they wouldn't be there as a backup.
So yes, this is a NEW thing.