The Chromium-based Edge will launch later this month and Microsoft has started sharing essential information about the browser. Microsoft plans to use ‘Experimentation and Configuration Service (ECS)’ in Edge to request and receive different kinds of configurations, feature rollouts, and experiments. If you want to be on a safer side, you can disable Microsoft Edge’s communication with the experiment service by installing the Microsoft Edge group policies. Microsoft warns that disabling the communication with this service could affect the company’s ability to patch bugs in the Edge browser.
Source: https://www.bleepingcomputer.com/news/microsoft/how-to-stop-microsoft-from-testing-new-features-in-edge/