So the Han, predominantly.
So there's still the issue of the Han displacing the indigenous peoples of the island chain. I am not as familiar with that process. I don't believe it was similar to European settler colonialism, given what I know about Chinese political history and their long commitment to peaceful coexistence. But it's something that ultimately needs to be processed by the Chinese and the indigenous peoples there.





I assume by "the nationalists" you mean the KMT, but the large migration of the Han to the island happened in the 1600s.
And doing a little more research (thanks for the impetus) it looks like that migration was a process that was initially driven by the Dutch East India Company.
Then it was driven by occupying it with Chinese military to keep the Dutch out.
But that process never stopped and Han settlers became dominant over the next century.
Then the Japanese imperialized. Then the KMT terrorized it.
But the original indigenous people still live there and the national question will likely arise at some point after reintegration.