Here is a key statement in the article:
"The UN is yet to officially confirm Buenos Aires announcement, but according to Article 76, paragraphs four to seven of the Convention, the coastal state can
“delineate the outer limits of its continental shelf, where that shelf extends beyond 200 nautical miles from the baselines …”
So basically Argentina has said; Article 76 says I can define the limits as I see fit. Now let the international community challenge that my decision. There has been no "ruling" by the UN. The link is a list of recent rulings:
LINK