To my knowledge, there are only very few flights between North America and South America that have first class cabins, namely the few 777w flights on AA (JFK - EZE, JFK - GRU, MIA - EZE, DFW - GRU). I've been following availability on these 4 routes (for travel in January - February 2018) for several months now, and not a single EF alert has come through. I cannot assert that not a single A seat has become available on any of these four routes on a single date in either direction, but that is definitely my impression since I began watching (in late September).

My query is whether others have noted this lack of availability as well.

[I don't recall seeing blackout dates in the xONEx fare rules, or an alert on the OneWorld site that "A" availability is blocked between N. America - S. America (or even a FT sticky up above about this state of affairs), so I assume that I've overlooked a prominent announcement. A link to it would be very much appreciated.]