The Manchu coastal prohibitions certainly made Coxinga take notice, but in the short term, they may even have helped him. His raiders raced to pick through whatever was left behind, and carried off what food and supplies they could from the abandoned villages before the Manchu demolition teams arrived.SOURCE: Coxinga and the Fall of the Ming Dynasty, by Jonathan Clements (Sutton, 2005), pp. 186-187
The Manchus did not particularly care where the local population went; they merely wanted them to leave the coast. Leave they did, but many sought refuge with the Ming loyalists, who arrived to ship them across the straits to Taiwan.
Although the defeat in Nanjing might have finished Coxinga's reputation as an adversary of the Manchus, the ranks of his followers were swelled by thousands of disaffected coastal dwellers, who preferred to head east and out to sea, instead of west to an unknown fate on land. Zheng family ships took refugees in their thousands to colonies on Taiwan, swelling the Chinese population there.
As time passed, the effect of the coastal prohibitions began to make itself felt. [Coxinga defector] Huang Wu had been right – the removal of any coastal dwellers seriously damaged Coxinga's ability to obtain supplies from allies inland. Communication with the distant [Ming] Emperor of Eternal Experiences became more difficult, and the Zheng family clung only to a few coastal islands such as Amoy and Quemoy. However, Coxinga's fleet and followers remained supplied from anew source. Chinese refugees established in military colonies on Taiwan were able to clear land and farm new crops for the Zheng organization. Mainland China might have been all but lost to Coxinga, but the Taiwan Strait continued to keep a Manchu counter-offensive at bay.
Protected from his enemies by the sea itself, Taiwan could be the perfect place from which Coxinga could plan his next move. It might take years to rebuild his forces to a level suitable for a repeat performance of the march on Nanjing, but Taiwan had the resources to make such a project possible. There was only one small problem.
The Dutch would have to go.