Traditional "local" Console gaming is defined as gaming on consoles and handheld devices where the game runs on the local hardware.
Cloud gaming defined as reliance on remote servers for game processing & streaming the video and audio to the player's device.
Examples of current Cloud Gaming providers:
Playstation Now, Microsoft's Xcloud, Amazon's Luna , Nvidia GeForce Now
RESOLUTION CRITERIA
A number of reputable research firms or Market Analysts will need to confirm Cloud Gaming Monthly Active Users (MAU) as higher than that of the MAU of Console Gaming.
Presumably, Cloud Gaming services will also want to notify the public & gaming media if/when this occurs as companies like to draw attention to their successes & certain players (e.g. Amazon, Microsoft, Nvidia) are public
I'm open to alternative measures (especially if quantitative & objective) if they can be justified as better aligned to the question at hand