I'm getting conflicting information, I'm hoping if I could get clarification here.

I have Emirates & LATAM flights as following in one Emirates first class ticket for both ways. I booked directly from Emirates website.

Bangkok, Thailand > Dubai, UAE (Emirates flight, First Class)
Dubai, UAE > São Paulo, Brazil (Emirates flight, First Class)
São Paulo, Brazil > Santiago, Chile (LATAM flight, Premium Economy for outbound, Business Class for return)

Someone told me that when I arrived in Brazil, I'll need to go through immigration/custom, collect baggage and check-in again. I thought that was for connection to catch domestic flight within Brazil. If I'm not mistaken, for international connection, I'll remain in international area of terminal, and then simply get on next international flight without going through immigration. I asked Emirates and I was told that my baggage should be checked through until Santiago. They also advised me to reconfirm this when I check in at the first airport. Emirates booking shows my Emirates flight arrives at GRU in Terminal 3, and my next LATAM flight departs from the same Terminal 3.

Will my baggage be checked through all way to my destination in Santiago, Chile?

Thank you