I wish they would start releasing concert films and opera in 4K! It would be stunning.
These films would be something to see, but its pointless for general consumption. These will get converted to 4K and sold for a hefty price tag in a nice box. At either resolution they will look stunning. Even though I'm not a Bernstein fan, I would snag these just to have concert films in 4K.
As for an audio only release, it reads like they remixed for a 22 channel Atmos set-up, or something similar. Who knows though, it sounds like they were much more worried about the video. I would like to know more about it, too.