That's an odd example. askhistorians is meant to reflect current American historians' scholarly consensus, and rigidly moderated to stay that way. While this does sometimes produce insight it's one of the least debate-oriented places on the internet.
I've seen plenty of posts in which people had conflicting accounts of historical events, including anti-Western, anti-Eurocentric, and anti-Imperialist ones, and as long as they are well-sourced they are fine.
The bigger issue is that r/askhistorians is an English-language subreddit, and English is the most widely-used language of the Western-Imperialist powers, so it makes sense that if you ask in their language, you are mostly going to get their answers. The people who would have equivalent expertise from other viewpoints are mostly not lurking that subreddit.
And yes, it's not meant to be a place to debate, it's meant to be a place to get access to historians' subject matter expertise. When 2 historians' accounts conflict with each other, they aren't supposed to start arguing about it, they're supposed to each make a separate reply to OP with their sources.
