Apple CEO Tim Cook’s latest visit to China this year turned out to herald the launch of the iPhone Air on the mainland, as the country’s three major telecommunications network operators start commercial trials of the eSIM function on smartphones.China Mobile, China Unicom and China Telecom each confirmed on Monday that the Ministry of Industry and Information Technology approved the eSIM trials, as Cook later that evening joined Apple’s live streaming session on ByteDance-owned platform Douyin...