Why would they not just make all languages available to all versions? Seems kinda odd to me...
i've had this hypothesis for a while, but
i think it's because each region will have its own regional exclusives in animal crossing new horizons. if that is true then because the nintendo switch let's you play games from any region
it is possible you will not need an entirely separate switch to maintain multiple islands.
this seemed to be hinted at a few months ago when we got information from a latin american twitter user that the version of new horizons available in mexico will have its own latin american translation (different from the dialect of spanish from spain) including clothing AND holidays that reflect mexican heritage. this was when we saw that girl with eyebrows in a long flowing dress.
traditionally animal crossing games have been released across the world with their own special version for each region (NA, EU, JP). there would sometimes be different items or holidays only available in each region. even on the original nintendo DS, which was a region free handheld console, a copy of animal crossing from one part of the world would be considered a different game with different save data compared to a copy from another part of the world. (save data was also stored on the cartridge but that's besides the point.)
if animal crossing new horizons is also split into regions then i think it means that we will have a situation similar to splatoon 2. although it is technically the same game and you can play with anyone across the world who owns the game via online, if you insert an NA cart of splatoon 2 and a JP cart of splatoon 2 your switch displays them as two different games with their own save data, even if you use the same nintendo account. this is because each region had its own in-game events, localizations (translations), and DLC specific to that region alone (though there were crossovers when it came to worldwide events).
if animal crossing is region split, then why has nintendo made the one switch one island rule very clear?
i'm guessing it's because the vast majority of players will buy the game for their own region. only the hardcore or travelers or foreigners in your country are likely to import games from other regions. to avoid confusion nintendo has probably tried to hammer home the one console one town thing. but
if animal crossing new horizons really is region split then we will not have to buy a new switch to play a second town. thank god importing a game isn't as expensive as buying a whole new console.
anyways that's just my hypothesis. the fact that the language options displayed on the eShop page vary across regions seems to strengthen it.