https://www.theverge.com/2018/6/13/17456908/twitter-live-news-events-timeline-notifications

Twitter’s quest to create a definition for itself that everybody can understand is turning another corner today. At the top of your timeline — or perhaps even in your notifications — it will alert you to live events and present a curated list of tweets about them. These new screens may include live video, and they are designed to help users find the best and most relevant tweets for ongoing live events, like a big baseball game or breaking news about an earthquake.

Twitter says it may send you a personalized push notification if an event is happening that it believes you’ll be interested in. It will also put those events at the top of the main timeline when they are relevant, along with big pictures and a little text encouraging you to tap in and explore.