I don't read it that way. That device has analog dimming with the level set by the voltage on the EN/DIM pin. Read 'EN' as digital enable and 'DIM' as the analog voltage but you would normally use one or the other, not both.
With PWM drive, the logic low voltage will always turn the LED off, the logic high will turn it on at whatever the high voltage is. The data sheet suggests a 45K pull-up is already inside the IC to lift the pin up to internal Vref so all you have to do is pull it lower with external circuits. An open collector/ open drain PWM driver would do the job without additional components.
Brian.