Were they used to flying with Low Fuel captions so desensitised?
"LOW FUEL" is LOW FUEL. Triggered by a thermistor on the side of the fuel quantity transmitter. It is independent of the quantity system and part of the WARNING system. ~ 8-10 minutes remaining.
To get to that point you would have already passed "FUEL PUMP AFT or FWD" WARNING as appropriate which is triggered by measuring the current going to the pump and a time delay in the CPDS.
You would also have the CAUTION "FUEL" which is part of the quantity system indicating a total of the supply tanks being below a certain level.
If "LOW FUEL" captions were ever the norm and someone was desensitised by it something went wrong somewhere in the chain of events leading up to this accident.