How was it decided that the following three should be grouped together: "Native American, Pacific Islander, or Indigenous Australian"?
Doing a google for this phrase gives pretty much only Stack Overflow/Exchange results, from the results of surveys from past years.
If the answer is “We consulted expert X and they said Y and Z”, that’s fine, I don’t expect Stack Exchange to do their own research, but I’d like to know the rationale.
Update In the 2020 developer survey, the following option was given, to a question which didn't use the word "racial" or "ethnicity":
Indigenous (such as Native American, Pacific Islander, Or Indigenous Australian)
This would suggest that in 2019, the designers of The Loop thought back then that the three groups had that characteristic in common.