Do you have any particular evidence to support this claim?

The code comments are pretty clear tells

https://music.apple.com/includes/ipod/web-music-ipod.esm.js

They're all in regards to design choices or why something is needed when it's not obvious. And such a level of polish in the interface isn't something you attain through prompting. Not AI.

I don't really know what to tell you but the comments are definitely Claude. The result is pretty good but AI was definitely involved in the creation of this.