Via a support call to PTC, I was informed that the 'The permission for Reassign task/ Work item is hardcoded in WorkItemAdminActionsValidator.java. This action is only allowed for owners and Admins. There is no way to achieve this from Policy Administrator.'
Per my company's business practice, I want the people assigned to roles ‘Change Manager’ and ‘Team Leader’ to be able to reassign assignments. I don’t want to give the users in these roles to administrator privileges. It also is redundent to assign the users to descrete roles and to the 'Product Manager' role.
The abitlty to re-assign is basic functionality and the permission should be controlled via the ACL.