Airplay plays only 2.0 channel but upmixed. I think this might be Macos limitation or airplay itself limitation but the main issue is with LFE channel… it never gets played over airplay and for some reason other channels add bass which makes the sound muffled.
¦› Dolby Atmos Demo | Test Tones 5.1.2, 5.1.4, 7.1.2 and 7.1.4 (demolandia.net)
Here is a link where you can test these files… Bass testing doesn’t help from other places but this one over airplay won’t play Sub woofer at all. over HDMI it does play fine.