You'll never lose access to what you receive during your license year, even if you don't renew your license.
This is not like Netflix, you don't need to maintain a subscription to use what you've received.
Think of it like a magazine where you'd receive a new issue in the mail each month. If you chose to cancel that magazine delivery of course you'd get to keep all the issues you'd already received. That's true with Sunday Keys as well! You'll receive a new update to the Sunday Keys Sound Library each month, for as long as you keep your license active and that content will always be yours to access within the Sunday Keys App.
If you prefer a one time expense you can simply turn off auto-renew within your User Account. After your license year ends you'll no longer receive SK Sound Library updates or features exclusive to those with an active Sunday Keys License but will continue to be able to use the Sunday Keys App with all the Sound Library content you received up to that point.
Should you ever purchase another Sunday Keys license at a future date you'll immediately receive all previous content that has been released in the mean-time!