Apple today released macOS Sierra, the latest version of their desktop operating system for Macs.
Included in macOS Sierra is a feature called “Optimize Storage” which can help free disk space by, among other options, removing old, watched TV shows and movies from your iTunes library. It appears this feature is built into iTunes 12.5 (Preferences -> Advanced -> Automatically delete watched movies and TV shows.” From the macOS Sierra marketing materials:
When you need more space, Optimized Storage makes room by storing infrequently used files, email attachments, photos, and previously viewed iTunes movies and TV shows in the cloud
Activating the feature through the “Manage Storage” option in “About This Mac” adds (emphasis mine):
iTunes movies and TV shows that you’ve already watched will be automatically removed from this Mac. You can download them again at any time. You can change this later in iTunes preferences.
Except this does not appear to be the case: Apple occasionally loses the ability to distribute certain content, rendering a stop to any re-downloading of that content. From the Apple Media Terms and Conditions:
You may be able to redownload previously acquired Content (“Redownload”) to your devices that are signed in with the same Apple ID (“Associated Devices”). You can see Content types available for Redownload in your Home Country at https://support.apple.com/en-us/HT204632. Content may not be available for Redownload if that Content is no longer offered on our Services.
If you haven’t backed up a purchase and it is no longer offered by Apple, it’s gone, and presumably with no refund given that this scenario could occur years after you’ve made your original purchase.
macOS Sierra’s Optimize Storage feature complicates this problem by automatically removing content you may not have backed up. In fact, even if you use Apple’s own Time Machine, a file removed by Optimize Storage will eventually be removed from your Time Machine backup too once space runs out on your backup disk.
If you do everything Apple recommends (with the exception of what is in the Terms and Conditions, which we all read), you may end up losing some purchases.
(Hint: You can see what media may have already become unavailable for re-download by making a Smart Playlist in iTunes which includes the rules “iCloud Status is No Longer Available” and “Location is not on this computer.”)
Perhaps in the future Apple could move your purchased files to your iCloud Drive; this may not necessarily be considered a “re-download” as it’s merely a backup of one’s own files.
Hope this one gets sorted out soon.