Reading this book leaves you with more questions than you start with. Fortunately, you also leave with more insights and I think with every reread this story will reveal more depending on your frame of reference. 

I was reading On Women by Susan Sontag at the same time which gave me a very feminine frame to read this story through. It is rather glaring that the society the women create is still a cishet one that reflects the power dynamics present in one even without any men. I don't think this makes the story genderessentialist- it is the one thing the women can cling onto to connect them with their former life. The rituals of modesty, of community bring them comfort in a comfortless world. 

The interesting thing is how much of it reflects -or does not reflect- in the MC who has never known the world before the bunker. 

Either way, it gives a lot of food for thought.