The way they do it is they gather a focus group to test the audience reaction. It's just that sometimes, focus groups aren't that diverse and are representative of the audience that could potentially consume their material. Sometimes, they might feel like they're too big to fail and become complacent.

I do agree that movies are reflective of the current socio-political climate, or at least they should be. There are an increasing number of properties that do make an effort, but there are still those that are stuck in a bygone mentality. With awareness increasing every day, I'm sure that those who refure to adapt would be left in the dust.