As others pointed out, the real answer here is that if you want historically and culturally accurate Asian settings for D&D, which I agree would be utterly awesome, you should do as I did for Europe (and, for that matter, India) and WRITE a historically and culturally accurate setting.
On the other hand if what you want is to show off your totalitarianism through book banning, then what you ought to do is go fucking find someone to beat you to death to the great benefit of humanity.
Well that has been done to a degree for 5e with the
Unbreakable adventure collection.
Like Bedrock I did listen to a bit of the podcast and they made some reasonable points but also seemed to often over-reach to find offense to me. Also many of these supporters seem to be uncritically reading Said's Orientalism which has come under a lot of critique from other expert academics in the field for its historical errors, rather monolithic approach and lack of nuance (e.g. Simon Leys). This is the issue with reading one trendy book and not reading more widely, including the reasoned responses to that book.
I think the podcast also suffered as they didn't seem to have anyone on with a strong background on Japanese history, film and literature although Kwan did display more knoweldge than most and clearly knows a lot about China (believe he may be studying its history or is a teacher).
I think one of the strongest criticisms is with the honour system, OA seems to base most of the honour system on Bushido and applying that code to an entire society is pretty silly. It would be like enforcing the chivalric code on everyone in a European fantasy setting.
And while I liked OA when I first read it in the 80s I do now think it would have been better to not take the typical D&D kitchen-sink approach and kept it focused more on a Japanese-based setting, which is what it largely draws on, rather than mashing it together with more Chinese elements.
It's surprising to see this push to have the book removed as the hosts of the podcast even discussed things they liked in the book and were thinking of nicking for play.
But I guess this illiberal attitude is a common stance with the current generation unfortunately, even if it does seem to be in retreat more recently.