That's likely more on the writers than editorial.
Editorial knows about Arkham Games and Killing Joke, but I don't think they have so much control there.
In comics, the relationship between Barbara and Tim was exclusively friendship. And I don't know a lot about about the relationship between Bruce and Barbara in the past, but their relationship is mentor-student (sometimes even a father figure) in current continuity.
PS: Stephanie is usually paired with Tim.