It's possible to delete (or edit) class passes from your selection. Class passes already purchased by yogis remain unchanged after an edit, will not be edited retroactively, and will not be deleted either.
When a class pass have been deleted, it's not possible for yogis to book a class with the deleted class pass. This becomes an issue when yogis are still using the class pass. That's why we always advise you to temporarily uncheck the Yogis can buy this class pass online box when deleting a class pass for as long as they're still in use.
This way, the yogis cannot purchase the class pass online anymore but is still valid for the yogis using the class pass. When the class pass expire for all yogis, you can permanently delete the class pass from your selection.