No i think the answer is more simple. Asian people are mostly hardworking people, and hard learners on school, but they all seem to have a common problem, they simply dont speak any other language than their own.
And no matter what Chinese i go in my country, they hardly speak Dutch and when asked they also dont speak English. So they might have been there all the time, but silent. But i doubt its filtered by the goverment, cause Unreal doesnt contain any political stuff that needs to be blocked, and aside that, filtering is pretty recent and didnt occur 5 years ago. And if anything, than the gore in the Asian versions is likelly higher than lower. And this lies in the nature of Asian people to also have gore commics in an amount unthinkable to most western countries. Asians like gore

and certainly will never make a fuzz about it
And i also doubt net incompatibility because so far all the copies i have dont show anything like that, and i got the US version, the Dutch, Italian, German, Swedish/Norwegian/Finnish/Dannish , the UK version, the Australian version, and all seem to be compatible.
As for the Japanese version, because of WW2 the US is still highly involved in Japan, and that could account for the US version in Japan. But seeing the fact that small countries have their own versions, i am pretty much 100% convinced there must be a Japanese version as well because Japan has over 128 million people. That is certainly more than large enough to have a local version. I mean Australia has "only" 22 million people and they have their own version, so rest asured Japan has as well.
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