That isn't what I meant. Higher order doesn't "necessarily" mean more accurate. The results simply have different properties. The user needs to choose the differentiation order that they need. One interesting effect in data assimilation/modeling is that even-order differentiation can often have detrimental effects while higher odd order differentiation are better, but it is highly dependent upon the model.
This change in gradient broke a unit test in matplotlib (for a new feature, so it isn't *that* critical). We didn't notice it at first because we weren't testing numpy 1.9 at the time. I want the feature (I have need for it elsewhere), but I don't want the change in default behavior.