If you read the definition as a anything other than the the GO speed, if the rejected takeoff has not already been commenced, you ain't reading it right.
I don't think I've suggested otherwise, have I? I posted, "V1 may not be less than VEF plus the speed gained with critical engine inoperative during the time interval between the instant at which the critical engine is failed, and the instant at which the pilot recognizes and reacts to the engine failure, as indicated by the pilot's initiation of the first action (e.g., applying brakes, reducing thrust, deploying speed brakes) to stop the airplane during accelerate-stop tests." Ergo, if you reach V1 and have not already initiated a reject (brakes, power, speed brakes) yes it's GO.
Though I did work with a guy who did a successful reject after V1 (RAAF Herc) after a bird strike at Darwin. Distance to run markers on the runway undoubtedly aided his decision making in the circumstance, he had doubt as to the damage sustained and if it was flyable.
Perhaps he had the Electra N5533 accident in mind.