Agreed. I have a lot of songs in iTunes (digitized from old vinyl albums and CDs) that are not avaiable on any streaming service. Apple says those files will be accessible on the new Music app. Quoting the Apple homepage about the new Music app:
“…listen to all the music you’ve collected over the years. And find it all in your music library on all your devices.”
Apple would be crazy not to allow access to purchased music in an app called Music. So I am not worried.
And it is long overdue to boot movie/tv/videos and podcasts from iTune/Music.