Break it down further though. It doesn’t make sense by their own logic.I tend to agree but they aren't alone in fudging what constitutes atmos or even basic surround sound. Certainly Apple stretches it to the limit.
Arc + Sub + 2 Ones = 5.1.2
Beam (Gen 2) + Sub + 2 Ones = 5.1.2
Arc + Sub + 2 Era 300s = 7.1.4
Beam (Gen 2) + Sub + 2 Era 300s = 5.1.4
The extra “2” in the first figure of the second group would be the addition of the side channels, provided by the multidirectional sound of the Era 300s. By their own previous admission, the Arc and Beam Gen 2 are both 5.x.x systems used alone and therefore should both become 7.x.x with the addition of the Era 300s.
I don’t know, I’m a huge Sonos enthusiast and obviously Apple loyalist, but not gonna be pleased if they just start making up their own rules on how home audio works or is rated. We’ll see how it actually shakes down in official documentation soon enough.