Earlier quoted context omitted.
Maybe they grew tired of Americans pronouncing it wrong (most V are still pronounced as F, Vettel, Volkswagen etc.) ;-) Edit: This German apologizes for an attempt at a humorous / sarcastic comment and will revert to work-machine state at once. Beep boop.
Americans are pronouncing it perfectly correctly as most of us speak English and not German.
And yet, English has an "f" sound. German has an extremely consistent spelling and essentially all "v"s are pronounced as "f". We share (the latin) alphabet, and English has absolutely no authority, given how inconsistent it is.
Given that, I will say the voiced "V" when speaking English and the unvoiced, as necessary, speaking German.