If I'm reading it right, if you subscribe, you get unlimited storage for cloud backups of your content.
If you don't subscribe, you still get cloud backup, but it's limited to files you've used in the last 50 days (files will no longer sync if left unopened for 50 days).
If you don't subscribe, you still get cloud backup, but it's limited to files you've used in the last 50 days (files will no longer sync if left unopened for 50 days).