I wouldn't put it that way. It has more to do with avoiding too much repetition and making sure the front page isn't completely dominated by hot controversies, which would defeat the purpose of the site. (I hope everyone remembers what the purpose is: intellectual curiosity. See https://news.ycombinator.com/newsguidelines.html.)

Here are some recent explanations I've written about this:

https://news.ycombinator.com/item?id=21208169

https://news.ycombinator.com/item?id=21199248

https://news.ycombinator.com/item?id=21197771

HN has been flooded with China-related stories in the last couple months and most especially the last few days. They have been the dominant topic recently, understandably, as they are some of the leading events in current affairs right now. Important as these stories are, HN's core value being intellectual curiosity requires going easy on repetition—any repetition about anything.

There's a power-law dropoff in curiosity as a thing gets repeated. Other emotions—such as indignation—work the opposite way, so this is an existential issue for this site: the more repetition we have, the more HN's purpose gets drowned out and replaced by something that is inimical to it. This is the explanation of hamandcheese's conundrum upthread, about how a story about the ongoing struggle in Hong Kong, with lots of upvotes, can possibly be ranked lower than something called "The Origin of the Foot Rail". The answer is that indignation is by far the most powerful force on the internet, and as moderators our main job is literally to moderate that, so quieter, odder, less important but more curious stories have a chance to flourish.

If we didn't do that, HN would simply become a political outrage site like most other places. The front page would always be the top 30 outrages in the world, or more likely the top 5 outrages repeated 6 times each. That's the default, so if you want to run a site for intellectual curiosity, you need countervailing mechanisms. Here the countervailing mechanisms are software and moderators. But software+moderators also get many of these calls wrong, and we rely on users to let us know about those cases.

I know that users who feel strongly about these stories still feel like they're under-represented. But it always feels that way about any topic on HN that you feel strongly about. Frontpage space is the scarcest resource here, and there's never enough to go around. Even if your story is the most-covered story on HN, if you feel strongly about it, you will probably feel like it's being unfairly suppressed. As I've said too many times already: even Rust hackers probably feel that way.

If you read about the significant-new-information test in the first link above, the best way to help us with this is to let us know which stories have the most significant new information, relative to which are the follow-ups and copycat pieces. Then we can downweight the latter and help attention focus on what's significant. hn@ycombinator.com is the best way to let us know things; if you try to tell us things in the comments, odds are we won't see it.