"Maria is a foreign exchange student."
Standard Japanese is based on Tokyo dialect. "based on" does not mean "equal to". Therefore I personally don't think it should be pronounced like that. At least not solely for this reason. I think they should go for the most common pronounciation. Only when there isn't one pronounciation clearly more common then they should go to the default Tokyo dialect.
Anyways, I think we'll have to agree to disagree on this one :)
Actually kids may write Japanese like that when they're learning kanji, and Duolingo apparently accepts りゅうがく生 in other exercises already. That is done sometimes with some difficult non-joyo kanji even in formal context: 鬱病 is often written うつ病 and I've seen ad signs with 皮膚 written as 皮フ. But please don't do it with common kanji that you already know.