BEIJING—Tencent’s WeChat has temporarily suspended registration of new users in mainland China as it undergoes a technical upgrade “to align with relevant laws and regulations,” China’s dominant instant messaging platform said on July 27. “We are currently upgrading our security technology to align with all relevant laws and regulations,” the company said in a statement to Reuters. “During this time, registration of new Weixin personal and official accounts has been temporarily suspended. Registration services will be restored after the upgrade is complete, which is expected in early August,” the statement said. Weixin is the Chinese name for WeChat. Shares in Tencent plunged 9.0 percent in Hong Kong on that day amid widespread market jitters over Chinese regulatory crackdowns on high-growth sectors, including online platforms and most recently, private tutoring. Hong Kong’s benchmark Hang Seng Index fell 4.2 percent. China is in the process of tightening policies towards privacy and data …