I mean, I'd agree that the material is a thin slice of the society, but come on. These are real personal narratives of people who lived through these experiences. The implication that "the West" is why these books exist, not just why we're able to read them, is absurd.
Can you think of some that weren't, I dunno, 'Uncle Tom's Cabin' or Huck Finn? The notion that a survivor's memoir like Shalamov's is some kind of Western plot was absurd in its time and plainly disgusting now.
No no no no no no. How do you jump from one to the other? That's like saying Anne Frank's diary's credibility is tainted by the injustice of the internment of US citizens of Japanese ancestry.
I think the parent comment is reductive in a the-opposite-of-insightful way but no, that literature was not "funded and promoted by the West because it supports the western society discourse."
Not everybody was living in a prison camp in USSR, not even a majority of the population. This kind of literature was funded and promoted by the West because it supports the western society discourse.
Person who judges life in USSR by these kind of books will have a very skewed opinion.