There are two types of Knox Workspace license; monthly and yearly, based on its billing period type. A monthly license renews itself every month; therefore, it does not expire unless the customer or Samsung deactivates the license on purpose or specific expiration date is set when license is ordered in SLM.
However, a yearly license expires one year (or two years) after its activation date. If the license is not extended with an extension order and expires, the Knox Workspace container gets locked. But the data inside the container are not removed, and the user re-gains access to the container and data after the container is reactivated with an extended license.