As a side note, I had booked a flight out of Bueno Aires for my next destination, that flight had a transit connection at Rio. Naturally, the airline had similar notice of travel document requirements.
Now I wonder if without a Brazilian Visa, Boarding at EZE for a non-Brazil destination will be refused due to an airside Brazilian transit? This is just a postulated question for my own curiosity, as I will cancel that flight and my mileage deposited back. Nevertheless, someone with a definitive answer could give others some peace of mind.