This is thought-provoking, but I think I almost entirely disagree (which is rare for things you write!). The cognitive science regarding habits seems right, but the framing seems off to me.

I don't have time to formulate a careful rebuttal, so instead I'll just bring up the two main points that lead me to a different perspective.

First, my observation is that strictures about what is permissible are largely not arbitrary. Some are: which hand-gestures are good or bad are (save for those that mimic something that is non-arbitrarily bad, like being hit). Some aren't: meanings of "you = bad trash" are pretty universally, and pretty sensibly, not permissible. The boundaries of how to deal with impermissible actions also seem largely not arbitrary to me, but a consequence of how different societies are organized.

So your unsupported contention that what is acceptable is determined by privilege strikes me as mostly wrong. Because you only state but do not support the contention, I can't easily argue against it. But if you read Haidt, for instance, on honor cultures vs. dignity cultures--especially in the context of a society oriented around manual-labor vs. one oriented around white-collar pursuits--it seems to me that most aspects of culture have very much to do with the unavoidable demands of organizing life that way and very little to do with privilege (up to some arbitrariness in what labels we use for things and what meanings we attach to which fingers and how straight or curly one's hair is--silly stuff that doesn't even require much change in habits should we decide to change it).

Furthermore, your prescriptions here may intentionally be incomplete based on your intended audience, but as written they strike me as unwarrantedly capitulating, incredibly patronizing, or some combination of the two. For instance, when you say, "If I had lived through what they had to live through, I would’ve had the same reaction they did," and implicitly ask the same of "we privileged people" but you don't ask the same of the people whose perspective you're adopting, you seem either to (1) be advocating for a view that the presumption of privilege is in itself a sufficient argument for capitulation, and/or (2) arguing that the poor unprivileged dears lack your privileged ability to understand other minds and therefore their behavior cannot be helped, but yours can.

Of course, there are other ways one could plausibly read it, but these two most apparent ways seem totally reasonable for you to take on as a personal choice, and totally unreasonable to ask of anyone else. But a lot of the article is assuming or proposing that in fact a lot of other people do take a similar attitude, and the justification is missing.

Society is, typically, a sort of negotiation. In some cases, mutually beneficial arrangements can be worked out: everyone is happy, and indeed everyone can come close to being equally happy. But, for a variety of reasons, sometimes this is not possible and tradeoffs need to be made. This should involve consideration of everyone involved; it's fine to weight more heavily the concerns people who already are getting less than their fair share from society, but failing to represent the interests of large segments of society is not good.

This is, I think, the reason why the "political correctness has gone too far" numbers are so high. Those numbers argue against having us "change a lot of habits, [which] will not be easy at first". If the numbers are so high, it seems a pretty starkly clear condemnation of how the process is proceeding: it is doing a poor job of representing the interests of society.

So, anyway, with this level of support for the argument, I'm not convinced at all of the main thesis. Maybe there's a version with better support, or maybe I've misjudged the motive and/or implementation. But it doesn't obviously pass the "can run a complex society based on these principles" test from what I can see.