I think the only people it will set it back for are the #BelieveAllWomen, 'anyone who doesn't support Amber Heard is a misogynist' folks. They are very angry and upset and see this as a truthful victim being vilified for speaking up about abuse perperated by a monster. So their take away is that if a woman says she is abused, no one will believe her. I think for people with that perspective, it would make it harder to come forward.
I think that is a minority of people based on what I have seen online - most do see that Amber is lying and regardless of where they lie they have a more nuanced view of this than a woman spoke up and wasn't believed, and was attacked for speaking up about abuse.
From another angle, I have seen many people who are survivors finding this empowering because most don't get their moment in court to tell their side and to 'expose' the person who has convinced others that they are good and charming and the victim is the problem. I think some of the recordings especially have been validating for some people.
I also think it has opened up a discussion and a real life example of how women can be perpetrators and men can be victims and hopefully in the long run that leads to more anger management / perpetrator services for women and more victim services for men as both will help to reduce the abuse.
I think how MeToo responds will also shape the future role it has. If it takes a BelieveAllWomen tone - then I think many will turn against it.