It just came out today. The newsletter I mean, not the PDFs!Yeah just heard that news. Apparently I missed a newsletter somehow."We will share a complete PDF of the game to all pre-orders in the next few weeks." - from the latest newsletter
I think it's as simple as "so the egg knows when to open to release the face hugger."
@Riggswolfe, yes I agree the eggs are living entities. My though process was why do they need to be? I guess Kane was suckered into looking into the egg by it opening and that may be reason enough!