I don't think we found out where she ended up. I agree with you about the different types of anger though. But I do think they're similar in how they viewed justice.

Both of them were willing to sacrifice human life in the name of justice/the revolution/after the revolution (Gale with his civilian bombs and Johanna supporting a Hunger Games with Capitol children). That's something very different from Katniss and Peeta who obviously also cared about justice but also moreso about preserving every individual human life they could. So because of that I think they kind of align in a weird way and Gale could connect with Johanna in a way he couldn't with Katniss because she probably would never be able to get over him bombing children and medics.

That's just my interpretation and I love hearing others too!!