Ok where to start...
Does the thing where multiple colonial legacies are conflated with each other. It sounds like an ROC comparison (since he uses "consists only of Republic of Korea" as a comparison). https://twitter.com/ArthropodFrog/status/1325089780401627136

But also conflates this with the perceived behavior of Taiwanese Han settlers (started calling themselves "Jeju-nese")? These are both legacies that need to be dealt with, but it doesn't help to just jumble them together.

The difficult thing is that there's really no snappy response. Every time I see this is like a rabbit hole of explanation. The actual history is nuanced. Many Taiwanese Han (and other groups) weren't seen as Chinese for a while.

...And they had an oppressive dynamic with the Taiwanese Indigenous population. Exemplified by 鄭成功, but a legacy continues to this day (fears of Hoklo supremacy with the DPP).

One can acknowledge the privileges of Whiteness while also acknowledging the uneasy relationship with it. Similarly, you can acknowledge ways that you've benefited from Han and/or Chinese identity while also acknowledging your uneasy relationship with the labeling.

I hate to sound like a broken record. But what makes them think the CCP would be any better on dealing with Han supremacy, especially when oppression within China's borders is denied or ignored.