Hi,
I have double checked it.
the Reassign in this case is happening for two main reasons.
1) the user who is supposed to approve/reject(take action) can use the re-assign, to delegate his/her work-item to someone else.
2) a system admin can see the reassign button, always for the fact that it can reassign an allocated work-item to anyone for administration reasons.
There is another aspect, which is delegate, and behaves the same as re-assign (however delegate and reassign are two different things, though produce the same output, so let's move to further details, as your question is not about delegate)
In the standard system, if a user has access to VendBankAccountsMaintain(a privilege), such a user will have access to all those option, as shown in the screenshot.
Reassign comes as part of System User Security role
Security Roles >> System User >> SysServerAXBasicMaintain(Security Duty) >> WorkflowEssentials(privilege) >> WorkflowReassignWorkItem(Action Menu Item)
The trouble is, if you take-off (remove access) of this action menu item, a user would not have reassign for any workflows (not just this workflow)
given the situation and facts, I see only two possibilities.
1) customization to disable the reassign for specific workflow(s) only.
Or
2) without customization, disable the reassign for all workflows
