While it was initially reported that iTunes would live on in macOS 10.15, it now looks like the app will be retired, over 18 years after it was introduced by the late Steve Jobs at Macworld on January 9, 2001.
Apple will be replacing iTunes with standalone Music, TV, and Podcasts apps in the next major version of macOS, expected to be unveiled at WWDC 2019 next week, according to Bloomberg's Mark Gurman:
End of iTunes
iTunes has been the way Apple users listen to music, watch movies and TV shows, hear podcasts, and manage their devices for almost two decades. This year, Apple is finally ready to move into a new era. The company is launching a trio of new apps for the Mac – Music, TV, and Podcasts – to replace iTunes. That matches Apple's media app strategy on iPhones and iPads. Without iTunes, customers can manage their Apple gadgets through the Music app.
This information lines up with a recent report from 9to5Mac's Guilherme Rambo, who claimed that iTunes will be renamed to "Music" on the Mac. In other words, iTunes is going away and will be replaced by the new Music app, which is expected to become the new utility for syncing and managing Apple devices.
Steve Jobs quote from Apple's press release about iTunes in 2001:
Apple has done what Apple does best — make complex applications easy, and make them even more powerful in the process. iTunes is miles ahead of every other jukebox application, and we hope its dramatically simpler user interface will bring even more people into the digital music revolution.
Here's what iTunes looked like in 2001: