China is considering asking media companies from Tencent Holdings to ByteDance to let rivals access and display their content in search results, a move that could further eradicate online barriers and shake up the internet advertising arena. The Ministry of Industry and IT is debating rules to make hundreds of millions of articles on Tencent’s WeChat messaging app available via search engines like Baidu’s, people familiar with the matter said. It’s also considering making short videos from ByteDance’s Douyin — TikTok’s Chinese cousin — show up in searches. Regulators are polling companies for feedback and it’s unclear whether they will...