Symptoms

Can any standard K2 component synchronize (create/re-create) to SharePoint user accounts which were removed from SharePoint?
 

Diagnoses

K2 uses SharePoint Site Collections as Group Providers: Group Providers are registered to enable the use of SharePoint Groups. When installing K2, a Group Provider is automatically registered to the Process Portal created by the installer. Should the need exist, Group Providers can be manually registered on other sites by selecting K2 Workspace andgt User Managers andgt Group Providers and clicking Add (source).

K2 by itself/as a platform only pulls users/groups for SharePoint and by default it does not create any users or groups in SharePoint unless your K2 process/solution is not specifically designed to do it.
 

Resolution

K2 only pulls users/groups for SharePoint and by default it does not create any users or groups in SharePoint unless your K2 process is not specifically designed to do it.