All history is revisionist history. It's not an objective field of study, so nothing is ever "settled."
As I think I posted elsewhere (or maybe it was earlier in this rather longish thread), when we hate the new interpretation, we scornfully call it "revisionist," as it has just been made up. When the new interpretation is one we agree with, we call it "proof positive."
History is always seen through the lens of the present, with the present's ideals and prejudices coloring it. That was the case when the "original" version that we agree with was written, and it will still be the case long after we have decayed to dust.
Oh, the Civil War was about slavery. The people who mattered, the planter elite, and the few others who had any input, made it very clearly that that was why their states were seceding.
Why men fought--that is a different subject.