I think that is great that it would be required if they are to be on the App Store. If they can use a browser outside of Apple APIs and bring their own customers, Apple does not care. That means they are not using Apple’s resources for free, but Apple gets the benefit of their customers having access to their gaming platform.You know it's ok for MacRumors to express an opinion on this matter rather than just quote Microsoft's. Requiring individual games in the xCloud to be submitted and bought through the App Store is a bad user experience. Requiring that these games be individually vetted by Apple is particularly laughable. Apple is pissing against the wind here and the customers are getting splashed as the result.
While Apple makes money from games, it casual gamers and they will use what’s on the platform. Serious gamers have never been Apple’s customers, so this would just icing on the cake.