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