It's seems stupid, but are business. Yeah, CONCACAF offered a 16 team tournament but only with CONCACAF organization, and obviusly only them earning the profits and TV rights, and Televisa or Univision winning those TV rights, because they are partners in this. What would you expect from CONMEBOL? And, obviusly, CONMEBOL also doesn't want to share profits and they have their own TV partners, Globo Sporte or Torneos y Competencias. So, Mexico or USA would give priority to Gold Cup until now, because for now on Copa America will held evey four years as the same of EuroCup and the Gold Cup still have this two odd year format. Mexico wants to join if not interferes with Gold Cup. Team USA? I don't know what they want.