I might be way off here, but I've always wondered if the body has a kind of folk memory, otherwise how would animals know what dangers to avoid? Perhaps that sounds silly; I certainly don't mean to trivialise anything.
I have thought that about when children 'remember' a grandparent they never met. Almost every function of the body a baby 'practices' in the womb, sucking a thumb or stretching. I don't see why brain cells that will be storing memories don't have memories from the parents.
I have seen Schindler's list and read some Primo Levi. My mum was appalled that when I was at school I read ,'when Hitler stole pink rabbit'. I was about 9 or 10 and it really gave me a sense of what would be like to be a child and have to move country with very little.
Strangely my mum had no problem with 'The world at war' being on with me in the room when I was much younger.
I think there is a lot to be said from reading / seeing the story of an individual or a family, I think it was Stalin who said, "a single death is a tragedy, a million is a statistic", the story of a few people is more personal and hits home more than a documentary.
I think one reason there are so many books now is that the generation that survived are dying off, if their story is going to come out ever then this is sort of a last time it can.
Many who did survive did not tell their children what they went through, but were able to tell grand children or strangers.
Sorry I'm not really contributing to the discussion.
There is one thing that I think might be interesting. I watched a documentary about the children of nazis. Some were the children of the camp commandants or grandchildren of.
One thing they all seemed to have decided was not to have children. They did not want the genes to be passed on.