I think we get two more civs, unless I'm mistaken, so here's a guess at that...
If European: Portugal, or Austria.
If American: Iroquois/Haudenosaunee, or Navajo.
If Asian: Vietnam, or Bhutan.
If African: Swahili, or Morocco.
If Oceania: Noongar, or Papuan (less likely).
My best guess is that it'll be a combination of two of the following: Portugal, Iroquois/Haudenosaunee, Vietnam.
If European: Portugal, or Austria.
If American: Iroquois/Haudenosaunee, or Navajo.
If Asian: Vietnam, or Bhutan.
If African: Swahili, or Morocco.
If Oceania: Noongar, or Papuan (less likely).
My best guess is that it'll be a combination of two of the following: Portugal, Iroquois/Haudenosaunee, Vietnam.