Earlier quoted context omitted.
It used to be called Persian in English, the media changed it to Farsi to reduce it's "prestige". If you knew English and you are old enough you even remember the shift (1990s–2000s).
> the media changed it to Farsi to reduce it's "prestige" This is not true. It happened after the 1979 Iranian revolution, when Iranians abroad wanted to call it Farsi out of cultural pride, using the same word in their own language, rather than Persian which is the "foreign" word for it (from Greek/Latin). It was literally reclaiming the name. Then the media followed suit out of respect. It was cultural sensitivity…
I think it just was a random occurrence / perfect storm in the US where some Persian speakers moving there didn't know there was an English word for it, and where the local population were more used to hearing names of unknown languages, and it happened to stick around and start spreading. And _then_ it maybe became a cultural pride or whatever thing with media following suit like you said