Doesn't this book prove that holocaust revisionism is right?

[Jack]

This book is heartbreaking, and I certainly don't want to minimize the tragedy of being interned in a labor camp in horrible conditions.

However, the claim of the Holocaust is that the SS wanted to systematically exterminate as many Jews as possible. Therefore why wasn't Primo executed by the SS before they left the camp? Why did the SS leave Jews alive in the camp knowing that the Red Army would liberate them? Doesn't this prove that there was no systematic plan to exterminate all the Jews?

I would appreciate if someone could help me answer this question. I've read this point being made in Debating the Holocaust: A New Look at Both Sides and I'm not sure what we should answer to revisionist historians.