SJW terminology often makes no sense. The term BIPOC "black, indigenous, and people of color" is a prime example. The term POC already includes black and indigenous. The only reason to exclude those is to establish a hierarchy (animals are equal but some are more equal than others).
The only logical reason to exclude indigenous from POC is if you are also talking about indigenous Europeans which are white, but I'm pretty sure they aren't.
Or they just want to tear down the tower of Babylon.