I have opened up a few times in which I think the one area universal apps will actually make a huge difference will be gaming. If a developer can make an XBOX game app, and get it across Windows 10 and Windows 10 for phone as well, that can only improve gaming on mobile.
If you are refering to XBOX Live intergration as being dead- maybe. Much like Rooms and Hubs, this feature needs to be utilized by users to get it off the ground. People like XBOX Live intergration, but it never really hit the criticle mass it needs to for it to be a mobile break away hit.
We just need more and better gaming options. Live is not all that needed in my book.
Moved this from "Off Topic Lounge" due to subject matter.