When ever we reverse the General Journal Entries the reversal is happening with out the Workflow process. So we want to remove the access to Reversal menu to the users. We identifies the List of roles, Duties and Privilege which provides access to Reverse the Journal entries. 

But System User role also has the privilege to Reverse the Journal entries. We duplicated the Accountant role and removed the "Reverse transactions" duty from the role and assigned just the Account Custom role and system user role to Test user, we are able to do the reversal even after removing the Duty as System User has the ability to do Reversal.

We do not expect System User to have the ability to Reverse the GL Entries, request Microsoft to please remove the reversal privilege from System User Role.