When a user is deactivated from the system, a reason for the deactivation may be logged during this process. This log can be found in the Admin module on the left side, and the Admin module is visible and available to system admins only.
In the Users tab, each user will have a vertical three dot menu that, when clicked, will expand a menu with an option for Deactivation Reason. Click on this to view the deactivation reason. If the option for a deactivation reason is not available, the user may not have been deactivated. Deactivated users will have a grey icon for their status.