That New York Times article is interesting, if it is indeed illegal to target propaganda to American citizens it seems that VOA did so in violation of law and only stopped when caught doing so.
That leads me to one of three conclusions:
1: Someone working for VOA felt that it was not illegal for them to do this making Business Insiders interpretation of the law at least plausible if not correct.
2: VOA knowingly used Facebook to target Americans with illegal propaganda.
3: Workers implementing VOA advertising were unable to understand that if you select "United States" as a target in Facebook's geo-targeting tool[0], that advertising indeed will be shown in the US.
Three seems the least likely to me personally given the historical context and since being skeptical of news releases is likely good practice anyway I'm not convinced that you shouldn't be.
To quote the same article:
Weston R. Sager, a lawyer with firm Gallagher, Callahan & Gartrell who has written about anti-propaganda laws, said that it was disturbing to see government-funded news agencies targeting Facebook ads at Americans, no matter their content.
“I’m concerned that we’re seeing the beginning of government efforts to try to influence public opinion in the United States through the B.B.G. and its affiliate entities,” Mr. Sager said. “It’s one thing to read a tweet by Donald Trump. It’s another to receive a very polished news story from an organization that holds itself out as objective and fact-based.”
[0]https://www.facebook.com/business/help/202297959811696