Microsoft has announced that the new Microsoft Edge will follow the same Adobe Flash retirement roadmap as Chrome and other chromium-based browsers. In July 2017, Adobe announced that it plans to retire Adobe Flash in December 2020 and it will also stop updating and distributing the software. The classic Microsoft Edge and Internet Explorer 11 will continue to have full flash functionality in 2019 and the company will not make any further changes to these legacy browser’s current Flash functionality. For these browsers, Flash will be entirely removed by December 2020 as originally planned.
Source: https://www.bleepingcomputer.com/news/microsoft/new-microsoft-edge-to-retire-flash-using-chromes-roadmap/