So I'm not sure that specific comment would be considered to be a "dominant western narrative" unless you're going to tell me that older (and so who have lived through it) educated people in China who don't speak a word of English have a western mindset because they're educated.
Accounts from well-off diaspora of any country will always be negative. It’s a self-selecting group with specific interests.
EDIT: By the way, it's not that hard either to find books written by Chinese writers not part of the diaspora that are critical of the cultural revolution (Serve the people by Yan Lianke, 3 body problem by Liu Cixin) or the great leap forward (4 books by Yan Lianke). Obviously, writers living in China that have to deal with censorship tend to be less directly critical of it compared to writers from the diaspora but that doesn't stop some criticism to shine through.a
I was curious about the 'narratives' it mentioned.
They might be wrongheaded; they might be valid.
Either way, it piques my interest.
This is extremely manipulative. The only reasons to say something like this are to shame the person you're respond to and/or attack and discredit them and force them to respond defensively. Don't do this.
(it also immediately outs you as not having any valid points to make, because someone with a reasonable response doesn't need to stoop to emotional attacks)