This is a great example of the dishonesty and pushing the agenda of discontent Think Progress has become famous for.
A spokesperson for the Argentine president denied the allegations.
Even though the writer has a clear denial of the rumor from a credible source, he is pushing the false rumor because it matched his desire to attack Trump and upset people. This is 100% partisan politics by the writer. There is no other reason to push a debunked rumor so hard.