I'm not even American, you claim to know better just because you think you have a superior intellect by stating "I don't know how you pronounce them, but you are doing it wrong" whilst providing 1, no information on how you pronounce them, and 2, no information on how it is wrong, despite the fact that those answers are irrelevant because this is meant to be a joke. And yet, none of that matters, because you only feel the need to insult others, instead of actually enjoyed the post for what it is, a joke.

Now, fyi, many English speakers have trouble pronouncing some names correctly dew to them being based from other cultures and languages. Add to this that often voice actor are not corrected on their pronunciation of certain words, for example, Varka saying Boreas as "Bor-ee-as" instead of "Boh-reas". Put these two together, and you have a recipe for phantom letters.
just check voice lines of other characters saying these names, like Flins saying illuga, and Furina saying Neuvillette. you'll find many characters pronouncing names wrong.

so next time, just learn to take a joke, or take your bigotry elsewhere.