Folks who like to stream or generally create content around their PC gaming exploits have had a less than satisfactory time of it so far with DX12 titles from the Windows Store, like Gears of War 4 and Forza Horizon 3. All that is about to change with XSplit as it has announced it will now be supporting direct capture from these games.
The method to capture from those games to this point involved a less ideal solution of directly mirroring the monitor into the software. Other, pre-DX12 games don't need to do this, and XSplit can just detect them and pull the feed directly. It's a much cleaner solution. With the new versions of XSplit Gamecaster and Broadcaster, DX12 games will be able to do the same.
The feature is in beta right now and you'll find more information and download links over on the XSplit blog.