Multiple Apple TV default audio outputs?

They just disabled the feature, you cannot longer select 3rd party speakers as your default audio output. You can still select your HomePods though, that’s why they did it.

But you can still play both at the same time, at least in my case, hold down the “Home” button on your AppleTV remote, the one that looks like a TV. And a menu will pop up on screen, in the bottom left you can select first your external speakers, get out of that menu, and then hold down the button again, and it will let you select your TV speakers, at least in my system it lets me.

Glad I could help. You’re going to have to do that every time you turn on your AppleTV though. Unless Apple decides to change it to the way it was. Drop a comment on the Apple feedback site, so they change it back.