My W's family was on board supporting our M and disowning her for her A; but my W responded like a rebellious teenager to their commentary and persuasions. I think my W's dislike for her mother pushed her to act in contrary to my MIL's leanings. Therefore, it was somewhat detrimental toward changing my W's behavior.
However, it did let me know that I was dealing with a stubborn selfish child who does not have a rational thought in her head.
And I've said it before; that my W is a different animal and I don't think DB'ing has had any effect on anyone but me. She's oblivious to any of my changes; except going dim and dark. Her incessant need to be liked by everyone and fear of abandonment pulls her closer to me when I pull away. But if I get too close; she pushes me away again.