In principle, an approval is required for parts that have an impact on safety or the environment. In case of levers, it is required for the brake lever (safety relevant) and not required for the clutch lever (not safety relevant).
There are different kinds of approvals. ABE is one kind.
I think of it as proof of quality, which I consider to be fairly important, especially if you consider how hard you need to pull on break lever at the NX to slow her down.