Kirk McElhearn:
With macOS 10.15 Catalina, and the splitting of iTunes into three apps (Music, Podcasts, and Apple TV), media files will be handled a bit differently. Here’s where the various files will be located.
It’s a beta, so this info could change.
Looks like Podcasts & Books are still the red-headed stepchildren of Media in Catalina.
Good grief, I hope they change that by the release. The issue with iTunes wasn’t that all media were stored in the same media folder. Typical Apple: fixing the part that wasn’t broken.