@tistou As of today (14 January 2020), 20H1 (Windows 10 2004 Build 19041.21) does not include EdgeChromium. EdgeClassic remains the in-built browser.
I am 99% certain that will change before release of Windows 10 2004 in April, and that EdgeChromium will be the in-built browser in the release version. In fact, I expect EdgeChromium to be in-built in Windows 10 2004 within a matter of days/weeks. It would make absolutely no sense for Microsoft to roll out EdgeChromium to existing Windows 10 users but not build it into the version that will be released post-rollout.
A caution, though: Microsoft has not formally announced that EdgeChromium will be built into 20H1, and at this point, I am speculating. Perhaps we will get an indication in the documentation that Microsoft says it will issue tomorrow.