I think it would be awesome to split the music side of Plex into its own iOS app. I really think the app could use some of the cool features and simplicity of PlexAmp to make a solid iOS music app.
I realize that the current iOS app supports music but it’s always felt secondary to the video support and I think splitting it off could mean better exposure to some of the music feature (cross fading, time travel, volume leveling, etc).
I don’t know if Plex themselves plan to release an iOS music-specific app, but there’s a third party one named Prism, which can connect to Plex libraries (amount others): https://prism-music.app