From this point the rest of the effluvium (90%) was packed full of eggs. It seems after the female caterpillar seals itself in the bag, it turns around before pupating, so the the head is facing the bottom of the bag.

My guess is she partially ecloses, and somehow slits the bottom of the bag open for mating. Or there is enough room for her to fully eclose, and she somehow gets her abdomen back in the effluvium (empty pupa case) to deposit eggs. Either way, it would explain why the male had his whole abdomen inside her bag while mating.

Within a week after mating, she fills the effluvium full of eggs and protective hair as she slides out of the rest of the pupa case and bag falling to the ground to die.
That is my theory.
Another possibility is the female was absorbed by the eggs.