It never made sense that it'd be locked to UWP games in the first place. Besides the things people complain about the platform, there aren't even that many games there anyway! But most importantly was the fact that the Xbox app in Windows 10 lists every game you own, UWP or Win32.
A lot of outrage over nothing in the end.
Sums it up nicely.
The thread title needs to be changed, and probably a new thread needs to be started when this feature is out, at least in beta.