I think you'll be fine.

For background, my understanding is that the reason O fares to South America aren't eligible for mileage earning is that AA uses the O fare bucket for consolidator fares on trips to South America. Therefore, I don't think O fares ever show as regular, purchased fares on those routes. In markets where O fares do show up as regular, purchased fares (i.e. not South America), they're eligible for mileage earning on AA. AS's policy is similar enough to AA's that it's hard for me to imagine them not being exactly the same in practice.