First, if youre going to do this, you’ve got to steel yourself for the backlash because some people will not take it kindly no matter what you try.
Second thing is that as soon as your book is outdated, people will be even more offended. Baby it’s Cold Outside and Huckleberry Finn are prime examples of championing that with time becomes an accusation of assault or racism.
The safest route when doing this is to not let anything go unchallenged for long, even if its an internal objection from the MC’s POV. Chanpioning has to be swift, objections faster. Doesn’t matter how badly you pull of the act of ostrization, if you can time the objections right.
Next, people dislike extremly close parallels or reverses to known events and cultures. A big example of that is an older episode of Star Trek called Code of Honor.
First, when the script was written, it was meant to be a take off on Asian cultures–the old dynastys. It wasnt supoosed to be a black and white thing. They cast African Americans, which pushed everything along the late 80s racial divides, along with the goofy Star Trek alien clothing. It became so much cringe that people cant see anything but making fun of African culture.
Another thing is peoole want to see the ostracized stand up for themselves and gain power that isnt granted to them by a token from the dominant culture. So this is less what is done, but who does it. Its not just racism, but Disney Princess syndrome. It’s fine for people to help, but the initiative has to come from a source that people won’t rip. Going back to Huckleberry Finn, the big objections stem from the language of a young white boy and him being the source of cultural change.
There’s also monolithic issues–or lack theerof. When the degraded culture is appears to support the ostracism, no one truly listens to the objections to see where they are against both the dominant class and the violence/rage of the subjugated class.
But if you stand where everyone is catching flack–as they righly should–there will be confusions over what is sympathy for the aggressor. So the more convoluted and real you get, the worse people will divide over if you handled it right.
But if you get really simple and straightforward, youre treating the reader like an idiot.
This is just overarching things to think about. The safest thing is to avoid any obvious parallels. That’s something a sensititvity reader is for.