Is Apple Music lossless/uncompressed?

It’s lossless but it’s not on par with Qobuz or Tidal and as highlighted by others it’s challenging and takes some ingenuity to get the source to your HiFi gear in a lossless format.  It’s only lossless with the source, your phone or I-Phone connected directly, hard wired, not over AirPlay.  I got excited when they announced lossless as they have a large catalog of music that rivals any service and it keeps you in the Apple Ecosystem if you have Apple products, but it’s extremely limiting when trying to implement Apple Music in your HiFi rig and it won’t quite match the top services or Amazon Music for that matter.  Their ALAC still compresses the file, unlike a FLAC file that streams in its native format. 
 

Yes, albums marked “Lossless” on Apple Music service is ALAC coded and has Hi Res potential after ALAC enabled DAC conversion, however we don’t have any hi end Apple Music streamers on the market so ALAC streaming is basically limited to Apple devices and several USB type portable DACs similar to Dragonfly Cobalt.

Apple Music streaming service is not comparable to Qobuz or Tidal streaming services due to absence of Hi End Apple Music network players - streamers on the market. 

Anytime you use Apple products or services you enter the Apple 'walled garden' that only works well with other Apple products. Some people like to refer to it as a 'walled jungle' to reflect the complexity and and challenges within - see discussion above. I tend to agree, and find other industry standards far more agreeable both technically and sonically.

Tell your friend to go with Tidal and Qobuz instead of Apple Music as they sound better than Apple Music and will always be lossless no matter what device you are using. Tidal now offers Tidal MAX, which is hi res FLAC files up to 24/192 just like Qobuz. Tidal has recently dropped its MQA. Qobuz has bigger selections of hi res FLAC files than Tidal. But either Tidal or Qobuz would sound better than Apple Music even the lossless version of Apple Music.