While you’ve been able to uninstall certain Windows 10 apps since launch, as of October, Insiders have been able to delete apps such as Calculator, Groove Music, Mail and calendar, Movies & TV, OneNote, and Xbox, but that’s no longer the case. Microsoft introduced the ability to remove unwanted stock apps in build 14936 for Windows Insiders, but now it’s taken back that option. I have not used a single app aside from Calculator and Weather. I was already a bit miffed that you couldn’t (quickly) uninstall certain apps, but it would really suck if you couldn’t delete any of the stock apps at all without going through additional steps.
This might totally be a bug, but BetaNews is telling me that you cannot get rid of stock apps unless you go through PowerShell with the latest build (15014).