SINGAPORE—Meta Platforms has struck a preliminary deal to sell a new, lower-priced version of its virtual-reality headset in China, regaining a foothold among consumers in the country 14 years after Facebook was shut out. The agreement with Tencent Holdings will make the world’s largest videogame company the exclusive seller of Meta’s headsets in China, people familiar with the matter said, offering the U.S. technology giant a major new market as it looks to boost tepid global demand for its niche gear. Tencent will start selling the headset beginning late 2024, with the two companies reaching a deal after about a...