US potential host 2016 Copa America

Not less important, its the fact that by then, CONMEBOL countries will be already worried on their own performance in the continental WC qualifiers ( also considering that Brazil once again will be competing for one of the few WC slots asigned to the Conference), which in fact will be much more important than any tournament that could take place elsewhere. Most countries, will not want to risk their best players in the panamerican tournament, as well. As any serious injury that they suffer, could complicate their eventual presence for the more important and much meaningful WC qualifier games, to come.

Very likely, that if the tournament takes place, only sub-standard CONMEBOL National teams assist to it.

Maybe, Maybe not. I am sure the organizers of this tournament want to make the most money possible for all parties involved. The only way to guarantee filled stadiums is to bring in big name stars. Maybe the CONMEBOL would have to delay the June Qualifiers (If the schedule is the same as this year.) and play them in July. Teams can use this tournament as preparation for the qualifiers.