Yes the iOS/iPadOS built-in Music app is a bug-ridden atrocity, but that doesn't mean a standalone Classical Music app is a bad idea. If there are to be separate apps, Apple should improve and nurture both of them as much as possible.
Example: ever notice how "Artist" in the iOS Music app doesn't mean the same thing as it has traditionally meant in the Mac iTunes/Music app? Instead, "Artist" behaves just like "Album Artist" in good ol' Mac iTunes (a more limited concept). Selecting the list of songs by [artist] doesn't bring up anything by that artist that appears on a compilation album, for example. Or collaborations. Idiotic. Oh and the app removed the great Genius playback feature a while ago. I have a better playback experience using one of my click-wheel iPods, compared to my iPhone.
BTW, the linked 9to5mac article says iTunes Pass will be rebranded to "Apple Account," not "Apple Balance" as this article says.