It seems likely that Eliezer noticed this early and possible that he kept it in mind while writing and editing later chapters. I noticed after that discussion (though maybe this is just confirmation bias on my part?) subsequent chapters started having a bit more social background that systematically favored "moderately big Magical Britain" (closer to 70,000 than 3000) and more political detail that seemed to me "more realistic" for the suggested scale.
There were a lot of slightly recurring cameos by people who made fan art, for example, so that you get more of a sense that the writing works a bit like the Simpsons with a relatively gigantic cast and a more available whenever the plot requires. And then there was subtle but direct stuff like the digression into the daily lives of Auror's guarding Azkaban with discussion of their alienation, working for triple pay (why official "triple pay"? why so formal? are their wizard labor unions?), and their silent culture of tolerated bribery. It smells to me like a small department within a much larger bureaucracy, or a platoon in an army, where people in the trenches together are reasonably OK pragmatically optimizing for mutual local benefit at the expense of the more sweeping institutions.
Also, apparently there are other schools in MoR!Britain.
Isn't a 70k population still too tiny to support the MoR-verse's level of social complexity?
Warning: As per the official spoiler policy, the following discussion may contain unmarked spoilers for up to the current chapter of the Methods of Rationality. Proceed at your own risk.
Assume HPMOR was written by a super-intelligence implementing the CEV of Eliezer Yudkowsky and assorted literary critics. What would it have written differently?
... is what I want to know, but that's hard to answer. So here's an easier question:
In what ways do you think Eliezer's characterisations/world-building/plot-fu are sub-optimal? <optional> How could they be made less sub-optimal? </optional>
(My own ideas are in the comments.)
To put it another way... Assume a group of intrepid fanfic writers in the late 2020s are planning to write a reboot. What parts of Eliezer's story do you think they should tweak?
And just to make sure we're all on the same page: Eliezer isn't going to go back and change anything he's written to bring it in line with anything suggested here. This is purely an "Ah, just consider the possibilities!" thread.
... which means that we can safely suggest drastic rewrites encompassing 30 chapters or something. Or change fundamental facts about the world.
(Exercise due restraint on this one. Getting rid of the Ministry/the Noble Houses/blood purism would probably turn the story into something completely different; this isn't what we're trying to do here.)
With that, let the nit-picking begin!!