The conclusions of the AJCN study referenced by the OP are not that rousing:

Conclusions
Currently available data provide low- to moderate-certainty evidence that dietary carbohydrate restriction to a maximum of 40% yields slightly better metabolic control of uncertain clinical importance than reduction in fat to a maximum of 30% in people with T2D. This systematic review is registered at http://www.crd.york.ac.uk/PROSPERO/...=CRD42017052467 as CRD42017052467.