If you mean over IE11, that's probably a (dumb, unhealthy) Group Policy decision of your Enterprise as Edge has been the default browser in Windows 10 since launch.
If you mean Edgmium (New Edge) over Edge Classic, it already replaces Edge Classic (entirely) when you install it, and there's a slow rollout through Windows Update already happening, with an attempt to converge on everyone having Edgmium sometime this year and Edge Classic dying a final, sad death (RIP, good friend, you served some of us well). They say fresh installs of "Windows 10X" the hyped dual screen build of Windows will only have Edgmium, and that'll likely make its way into other Windows 10 images over time.