Microsoft has now announced that Xbox Cloud Gaming for consoles has arrived for users in the Xbox Insiders program. This makes it possible to play games you haven't installed yet, and is a great way of trying out Xbox Game Pass titles before actually downloading them and potentially saves storage on your SSD.
It also makes it possible to play Xbox Series S/X games like Microsoft Flight Simulator on a regular Xbox One in 60 FPS and 1080p. There are a few issues reported, so we assume it will be a few months until the feature is launched publicly, but at least we know it's coming and is fairly close now.