Mani,
Yes, obsolete in 6.1 (and 6.0 also). You should also be able to confirm this by looking at what steplet calls the WOAddBAPI class in java. If anything does, then check for that step in the Agentry application and look at the dependencies to see if it is used. My guess if that if the step exists it is no longer tied to any transaction.
Jason Latko - Senior Product Developer at SAP