A new update is now available for Microsoft Edge Insiders within the Dev channel. The main focus of today’s update is the introduction of dark mode for the new tab page (NTP) and media autoplay blocking settings. There are a host of stability improvements, fixes and enhancement as well. Microsoft has also resolved the following bugs in this release: Microsoft has resolved several bugs in the latest update. Microsoft Edge has also added middle click support to Collections items and a new option to entirely block Microsoft Newsfeed (also known as Bing News)
Source: https://www.bleepingcomputer.com/news/microsoft/microsoft-edge-dev-channel-updated-with-media-autoplay-blocking/