Yeah, no.
Sure, she did all of her career in Argentina. She's not the only one to do that from Uruguay. That doesn't mean she's likely more relevant in Uruguay than in Argentina, where's she's one of many actresses or singers at the peak of her singles (like say, when ''Tu veneno'' was all the time on the radio). And unless things have changed a lot since her times in Muñeca Brava and the peak of her musical career, then nope, not one of our biggest stars.
But I won't argue against the way the rules have been set here. She works for those and she's probably a great choice, it's just looked odd that the number 1 person mistaken as Argentinian to be representing it.