Airplay 2
According to this article from March 2023 on the What HiFi website(see below), using Airplay 2 will change the music file in Apple music from lossless to lossy. Apple was said to be working to fix the problem. Has this been fixed yet?
As we have noted in our lossless audio explainer, the AirPlay 2 protocol supports lossless music (audio up to 24-bit/48kHz, in fact) so those with music files stored on their iOS device can send it over AirPlay to another device losslessly. However, the news isn't so good with regards to using AirPlay 2 to send lossless Apple Music streams. Apple Music’s Lossless streams supposedly convert from ALAC (Apple’s lossless codec) into AAC (Apple’s lossy codec) at a pretty lowly 256kbps when transmitted over AirPlay – and therefore not losslessly.
In other words, yes, AirPlay 2 does support lossless audio, but perhaps not for the use case you might want it to.
Apple is apparently working on an update to enable lossless over AirPlay (we are reaching out to Apple to confirm), so fingers crossed that this transpires and thus Apple’s lossless offering becomes validated.
iPhone SE, iOS 15