actually the biology behind the "empress" (even though its not canon) is that if a hive got to such a high population a queen whould metamorphisize into a empress "super queen" that would goveren over the hive in its entirty while several other queens would develop and if the empress were to die much like bees the remaining queens woul kill each other until the stongest was left to metamorphisize into a empress. thats the reason why in the avp2 human campaign you kill like 3 queens. but in any case the empress is so uncanon i dont really care for it myself. its not as bad as say the ravager but still its a rather large change.
"He who fights monsters should see to it that in the process, he does not become a monster." ~Nietzche