This was news to me. I tried accessing my music library through my existing iTunes app on my PC and it only showed podcasts and audiobooks as the only available media. So a little research and I discover that there's now a Music for PC app that must be downloaded. (I'd already known about the Apple TV app that replaced iTunes' video media.)

They did that on the Mac side of things about 5 years ago, and they're getting around to it now on the PC side. It's currently getting worked on the PC side along with getting access to iCloud and iCloud Passwords. The replacement programs on Mac work far superior to iTunes, and the only thing they haven't done with Apple TV on PC is get iTunes Extras working on videos you've purchased. That still needs to be done through iTunes.