well first of all where do you find diffrent eggs! you only recieve earth water lightning and the archon egg! nothing else!
well i hope its more then just a bug and i hope its more then just to recieve it on a later day of the event!

Wouldnt it be cool if you had to figure it out yourself? maybe like wearing your egg hat for a while and it "evolve" to the next level after it? or finding diffrent eggs during fightning mobs?