Since SAP HANA came in slowing old Business Objects are getting replaced by new Class which works.
Currently old Business Object are still working on new HANA systems, But dont know how long this will work. So I advice you to move to New Class BO’s.
BO BUS2081 is now replaced by class CL_MRM_WF_OBJECT and event as still same.
Will keep you updated as I come across more