Apple - Future of iTunes and audio files in its library
It is not a rumor - it has been officially announced by Apple that iTunes is going away. It is going to be replaced by Apple Music, Apple TV and Apple Podcasts in the next release of macOS named Catalina.
In practice you'll just start using the Apple Music program for listening to your old ripped CDs instead of using iTunes - so this is definitely not a dead-end. Your iTunes Library will be carried over automatically.
now that there are rumors that iTunes will be discontinued, is this a dead-end?
No, it's not a dead-end. There will ALWAYS be a way to play your own music files ripped from CD.
If not in an app called "iTunes", then in Apple Music, or a 3rd party application such as Winamp.
Continue ripping your CDs and collecting (and backing up!) the
.m4a files. You will be able to play them.
You'll still be able to play your music, even if you have to use other programs. For instance, the free and popular VLC multimedia player plays music in several formats, including mp3 and m4a.