It doesn't matter who hosts the south american championship. Sada is the current superleague champions (I think they won in the past 4 or 5 seasons), so as long as they keep winning the league, they will have a spot there. And I don't think home is a major factor here. South american clubs are not as good as Brazilians. Bolivar will not play, for example.
The hosts this year is Minas Tênis Clube. I don't know if you are Brazilian or not, but Minas is a state. Minas Tenis Clube obviously plays in Minas but their home is the capital of the state, and that's where the south american championship will be held in later this month. Sada's home is in the state of Minas, but not in the capital.
Damn, I forgot the 2nd qualified from Argentina is the champion of the dumb cup and not the runner up of the league. Without Bolívar, then no chance for ARG teams. Especially because UPCN sucks this season.
As for Cruzeiro, hosting in the state is still an advantage, they barely have to travel and many of their fans can still attend even if it isn't their home ground.