At first glance, I'd say Macri doesn't win the Argentine elections - the runoff was a rather close thing (51-49) and having him hiding his participation in offshore companies (and worse, if he reacts in the same way than IOTL but during an election campaign) should be enough to swing 10-15 thousand votes, resulting in a Scioli's victory.
OTOH, it was also revealed that a shady businessman linked to the Fernandez administration also owns off shore societies, but that affects Scioli in a more indirect manner than refusing to declare personal participation in the directory of several offshore companies