Re: The "Magical 3D" - I think they're referring to the launch version of Apple Music Spatial Audio which was an absolute disaster and didn't respect the Atmos fold down properly. I contacted specific people within Apple about this with sources proving what was going on and it was fixed within a month. I don't think it's ever going to return because it was a bug (or very poor decision) - Atmos has fold down into Stereo and Apple was applying their own Binaural renderer to it, instead of using the Dolby Binaural file - in fact, last I checked you still can't even send Apple the 3 files you need to get this right which would be:
1. Stereo Track
2. Dolby Binaural Track
3. Dolby Atmos Track
You can only send them 2. Which REALLY SUCKS, because you have to send #1 due to the ubiquity of Stereo across all devices, and have to do #3 to get the Atmos working (and "spatial audio"), so the Dolby Binaural render gets dropped and is instead a fold down of #3, which is not as nice.
It's very difficult to explain to an end-user which file should play when since it totally depends on what output devices you're using so I get why Apple went this way, but they further confused it with 'spatialize stereo' which honestly should just use the Dolby Binaural tracks... except Apple Music doesn't serve those (or accept them, last I knew). This coupled with the launch of high-res at the same time really made for an extremely confusing few months for Music Professionals. Then you get into 'downloading a copy' of music to your device and things get even more complicated because if you have a high-res Stereo version downloaded to your device but put on AirPods Max it won't play the Spatial Audio version, since those would be two different physical files.
They should have an option to download both and detect which device you're using (when possible, especially for their own headphones I mean come on they know when they're connected) and then play that back. And don't get me started on head tracking, JFC what a **** show that was.
On a more positive note, they've tweaked their renderer since then and now it works pretty well for the most part. If you have a 5.1 or Atmos Concert Movie it will work properly in Spatial Audio and it sounds pretty nice.