It would be awesome to have the Taíno, Muisca and Tupi from South America. I would leave Mapuche as a Modern Era Native South American alternative to Modern Era Brazil, Colombia and Argentina.
After all, the Mapuche are also known for fighting the Argentinians and Chileans during the 19th and early 20th centuries.
I'd be fine with modern Mapuche, even though they don't work quite as well with VII's idea of exploration versus modern civs. Although if they were modern, I wouldn't anticipate or want Argentina alongside them.
I am anticipating South America to operate more like Southeast Asia than Europe/India/China, where they hit all the "big" regions per era and expect people to pivot between them, instead of outright providing 3-era paths for each region. If I were to guess what that may look like:
* Antiquity: Taino/Arawak, Guarani (likely over Tupi), maybe Norte Chico
* Exploration: Inca, Mapuche, maybe Muisca
* Modern: Gran Colombia, Brazil, maybe Argentina.
Possible SEA layout for comparison:
* Antiquity: Khmer, Samoa, maybe Srivijaya (as "Malaysia" rep)
* Exploration: Dai Viet, Burma, Majapahit
* Modern: Siam, Philippines, maybe Indonesia/Brunei
That way you get the full spread of representation (one Peruvian civ, one Brazilian civ, one Paraguay/Uruguay civ, one Colombian civ, etc. etc.) without too much overlap. Then, maybe, if they are still adding civs after that, they could slide in extra era representation.