Two American siblings who were barred from leaving China for three years have now finally been allowed to return home to the United States – just days after Canada released Huawei executive Meng Wanzhou and two Canadians were freed from Beijing in an apparent prisoner swap. Cynthia and Victor Liu, who are both Massachusetts residents, returned to the US on Sunday after China lifted their long-standing exit ban. The sudden lift on their ban coincided with Canada’s release of Meng, a top Chinese tech executive who had been wanted in the US on fraud charges, after she reached a deal…