Lady Ada is wrong 
, and the datasheet correct.
Because when the voltage is below 3.3V the output of the KA75330 is NOT connected to GND, so the pull-up resistor keeps your regulator active.
When Vin is above 3.3V the regulator should be off. If not, your KA75330 is not working.
In your test, connect two AA bateries in series, make sure that they have about 3V. Replace the resistor by one of 100Ω. The led should NOT light. Otherwise the KA75330 is defect/fake.
If it works, then you need to reverse the logic of the KA75330, with something like the schematic proposed before.