I'm still bitter about this. I understand why Google kills free services that don't make money or no one actually uses but I've been paying for this service since it was released. My YouTube music experience has been worse in almost every single way. If it wasn't for Ad-Free YouTube I would cancel my subscription immediately.
As a side note one of the nice benefits was the data wasn't applied to T-Mobile data usage, I don't think YouTube Music will be added to this service.