Hong Kong’s ambition to become a regional data and innovation hub is threatened by an increasingly complicated web of security data rules and outdated local ones that complicate the flow of data between the two territories, according to experts. In a fresh blow to Hong Kong’s efforts to stand out as the gateway between China and the rest of the world, the Cyberspace Administration of China on Sunday published a draft regulation, which is open to public feedback until December 13, making it clear that certain mainland companies seeking initial public offerings in the special administrative region would be subject...