This study tells us nothing new. There is absolutely no causial link in this study, which is a
epidemiological one.
Beyond that - aspartame has been shown to increase hunger, and affect blood sugar level, in rats. We are not rats. Research in humans has shown no such thing.
The authors of the study say... "We cannot rule out that factors other than ASB (artificially sweetened beverages)... are responsible for the association with diabetes."
Correllation is not causation. We are not rats.