She wont get airplay with that song or any other song in America, a deal would work but only for the day and the days after would be all negative updates. Would be a total waste of money.
Her video's don't get many streams and Billboard only count US streams, and that's out of the window for her.
In all, would be a waste of time releasing a single or it would go flopney.
Why does this thread even exist? Her manager said it won't be released in the US and only possibly in the UK. It's used as a change of tempo in the show.
Nobody knows better than Susan Boyle and her people that, for all the reasons mentioned, she's an album seller not a single seller. And 5 years since her debut, according to the IFPI, she was still in the top 5 UK album sellers WW in 2013. I don't think the Boyle team spends much time agonizing about releasing singles.