No, it is not. We should be very clear that high BMI is, in fact, life shortening.

High BMI is, in fact, strongly correlated with atherosclerosis. It is, in fact, strongly correlated with decreased lung volume and risk pulmonary edema. It is correlated with clot formation and stroke. It is correlated with fatty liver disease. It is correlated with decreased bone density, which leads to a heightened risk of throwing embolism-causing clots if a fall leads to a break. It is correlated with a variety of cardiac events, mostly around hardening valves and fat buildup in cardiac tissue causing lessened output while there is more circulating blood volume. It is correlated with difficulties administering anesthesia or intubating patients in case of emergency. It is correlated with...

Being obese is still horrifyingly unhealthy even if high fasting glucose is just a proxy for some of those factors (which it is not, as this study is terrible).