Stereo, at its heart, is a phenomenological experience. Let's do a little thought experiment. Say you had one object that was able to exactly mimic the experience of sound coming from two discrete sources. You have one or more measuring devices to record whatever sonic characteristics interest you, and they come back the same in both cases. Is it no longer stereo because it came from one device even if the experienced product is the same?
So what does "true" surround mean? If you experience discrete sounds in a 3D space, does it matter how how the sound waves were generated or from how many sources? If your brain registers a sound coming from behind you, does it matter whether it's because of a speaker or because of sound reflected off of the wall if the experience is the same?
In theory at least, beam-forming is so different from traditional speaker technology that it's unhelpful to compare them in the same way. With beam-forming, the whole room in essence becomes part of the speaker. Reflection of sound of surfaces isn't a bug that has to be dealt with, it's an essential part of how the sound is delivered.
All that said, Apple isn't trying to re-create the experience of of listening to left and right channels to generate placement of sound in space. They're actually analyzing the signal itself to pick out different sounds and re-assemble them. It's even very different from concepts such as Dolby Surround. It's unique from other sound reproduction available through consumer products. I'm not saying it's better, we'll have to wait and see how it performs. They do provide the option of pairing two speakers to create an even larger soundstage and play with both channels. But until we hear the speakers themselves in both configurations, we can't comment on the quality. I wouldn't surprised if a single HomePod is a much better experience than cheap two-speaker solutions, with clearer and larger soundstages, but it's still not going to be able to compete high-end systems. Regardless, a single HomePod is NOT going to sound like a single traditional speaker.
But I think it's important to allow ourselves to re-think our concepts of sound and music generation. For the longest time our gold standard of music in the home has been the two-speaker systems as that's what was feasible given our technological limitations. That doesn't mean the two-speaker system is the final word and will always be the best method of generating an immersive music experience. I'm not at all saying that the HomePod is that device. Most of us haven't heard it and can't yet comment about its performance, and I doubt that a first-gen product to use beam-forming for audio is going to topple the existing music space. But I do think it has a very bright future ahead of it, and I wouldn't be surprised if future one- or two-speaker beam forming systems end up performing as well or better than many of the multi-speaker solutions in the consumer space.
TV can't "Hey Siri" see videos we've ripped in Siri searches, so it's also not a big stretch to imagine HomePod may be blind to ripped CD music, though I find that almost unbelievable if it pans out. I can barely believe $349 locked only to AM (excluding Spotify, etc) but will be further shocked if HomePod is even blind to the iTunes music libraries NOT purchased from iTunes or via AM subscription.
