people who have spread or been dispersed from their homeland.
“the Latin American diaspora has spread across the United States”
the dispersion of the Jewish people beyond Israel.
"a secular interpretation of Jewish history in antiquity and during the Diaspora
Just going off of what the first google result for those two terms says, I don’t agree with your conclusion that some of those countries are ethnostates. If, however, any or all of them did have a ruling party that included an ethnic background in order to join, then I’d be against that government.
It’s also possible to have a nuanced take on the subject. For example, if ethnostate “A” oppresses and kills members of a different ethnicity, while ethnostate “B” merely oppresses a different ethnicity, one can be against both governments while only being vocal about their opposition to ethnostate “A”, and not necessarily be amoral or hypocritical.