I heard the way they named Canada went something like this - when they formed the new nation, they picked naming letters out of a hat:
The first letter was picked and the man exclaimed “C, eh?”
The next letter was picked and he exclaimed “N, eh?”
Then the last letter was picked and he said "D, eh?, and that’s how they got C, eh, N, eh, D, eh (Canada).
Tough crowd. I’ll be here all week! Try the veal!
For the OP, I recall from the recent renaming of derogatory place names (e.g. ‘Squ__’) to indigenous names - one of which is Ojibwa Island in Lake Michigan. I know the Channel Islands in CA have indigenous names but they are not usually used when referring to them.
There were no natives on the Falklands for there to be a native name to revert to. Those islands were undiscovered before Europeans found them. It doesn’t matter which name is older, they’re both European names.
Given that “island” would be “airando” if transliterated into Japanese, I suspect that “Airani” is just the word “Island”. (With no distinction between singular and plural.)
The correct English (if so), I would think, would be Kuki Islands. Otherwise, you’d be calling it the Kuki Islands Islands.
Mumbai is mostly made up of seven islands. It’s not the original name of the settlement on the islands but it derives from one of the city’s native languages. (Bombay isn’t an English name, but is commonly held to be a corruption of one of a number of Portuguese formations.)
Taiwan was never the name of the entire island, but just a part of which that got applied to the entire island by Western people. What’s more, the name Taiwan seems to have gotten assistance from a dialect of Chinese.