Microsoft is reportedly testing 1080p for Xbox Game Pass cloud streaming.
According to Windows Central, anonymous but "trusted" sources sent screenshots of Hellblade running via xCloud, alleging that the streaming resolution was 1920×1080.
Up until now, the hardware had previously only been able to run in 720p, but it seems Microsoft is now planning to refresh the streaming servers from "Xbox One architecture" to that of the Xbox Series X. If successful, it will bring xCloud in line with other streaming services such as GeForce Now and Google Stadia, which already offer 1080p (thanks, VG24/7).