Windows 10 will start replacing the old Microsoft Edge (based on EdgeHTML) with the new Microsoft Edge (based on the Chromium engine) starting April 2021. This will be done automatically via the monthly Windows security update.
This is a good news for web developers as they won't need to test applications on the old Microsoft Edge. Google Chrome and new Microsoft Edge are both based on the Chromium engine. Edge also synchronizes its version in accordance with Chrome, so things will became more easier for developers.