removing users via SSO or adminconsole only deactivates users and does not remove them from workfront - https://steelcase.my.workfront.com/user
even if they were added directly in workfront they cannot be deleted.
not being able to remove makes the user listing a mess and over time could become quite extensive; especially when test accounts were created but no longer needed. there should be away just like other adobe products where we remove a user and can transfer any data associated with them to another user. and user is deleted.