I always thought Cass and Steph would make a great team to be associated with Batman Inc. Imagine how large Wayne Industries is. It's worldwide and it stands to reason that Mr. Wayne might send young bright interns or such to certain places. That could be Steph and Cass. Of course the real reason would be to check up on members of Batman Inc.
That would work, and it would get them out of comic book limbo, since there is no good reason to have removed them, since i don't think DC are trying to streamline Batman down to basics again, the removal of Steph and Cass struck me as a mistake.