Microsoft is set to allow you to start offloading apps that you don't use, as spotted by Windows Latest. The feature can be found in the latest Windows 10 Insider Previews from the development branch. Once you try to use an app that's been archived, the system will automatically download the app again for you to use.
If this sounds familiar, it's because Apple does it. This is actually a feature that debuted back in 2015 when Apple finally introduced an Apple TV that had its own App Store. In order to sell a 32GB device when a key selling point was the ability to load it with games, the firm came up with the ability to offload apps that you don't use. The feature later came to iOS.
And now it's coming to Windows, although presumably, it will only work for apps that come from the Microsoft Store. The system does need to be able to have a place to pull those apps down from. Inbox apps are probably a good place to start here, although any other Store app should work.
As for when this will arrive for non-Insiders, that's anyone's guess. The Dev channel isn't tied to a specific feature update.