BEIJING—The head of the women’s professional tennis tour questioned the legitimacy of what Chinese state media said was a retraction by a Grand Slam doubles champion who has accused a former top government official of sexual assault. WTA Chairman and CEO Steve Simon said Wednesday that a statement attributed to Peng Shuai and tweeted out by CGTN, the international arm of Chinese state broadcaster CCTV—which said it contained the contents of an email she wrote to Simon—“only raises my concerns as to her safety and whereabouts.” Peng is a 35-year-old from China and a former No. 1-ranked player in women’s doubles who won titles at Wimbledon in 2013 and the French Open in 2014. She wrote in a lengthy social media post earlier this month that a former vice premier and member of the ruling Communist Party’s Politburo Standing Committee had forced her to have sex despite repeated refusals. The post …