I think the comment you're referring to there was on "Than Hoa", more properly spelt Thanh Hóa. Interestingly, while doing the Khmer map, I found the source of this misspelling!
It's this awful map, still the first thing you see on the Wikipedia article for "Champa". Don't believe everything you read, folks.
USA's mapping of Australia is weird - almost like the USA is standing in for all 'first world' English colonies, given it has Canada too (though that makes more sense in DoC than in RFC, given Canada use the American city list too).
Actually, in the current map both China and Tibet's languages are functionally identical but for Lasa vs Rasa and the renaming of Pataliputra. My intention when making the Chinese map was to distinguish the Chinese names from the Tibetan ones, so that a Tibetan language map is more distinctive (ie uses the Tibetan language names).
Mapping the New World for civs that didn't historically settle there presents lots of interesting challenges. Let's assume for instance that the Japanese conquer Mexico; what city names are we to use here? A simple transliteration of a city like, say, Veracruz is one option (which I guess would be Berakuruzu, or thereabouts). But naturally this is assuming the Japanese when conquering Mexico would have translated a Spanish name, which seems farfetched. Then again, a simple translation doesn't work either - why would the Japanese, a Shinto/Buddhist nation who were intolerant to Christianity throughout much of their history, name a city "Holy Cross"? Translations of native names seem safer, and are far less without precedent, given the amount of place names in the Americas and Australia that derive from mangled western tongues making sense of place names already ascribed by the native population. But while this is easy for, say, the valley of Mexico, it becomes harder for places like the Sonora Desert, or the central American isthmus, where organised, urbanised settlements were virtually nonexistent. There's no right way of approaching this, but I think the challenge is worth looking at, given how often Arabia especially finds their way to the New World first.