All I'm saying is that Boeing are now fitting these lights to clarify the meaning of the warning horn when it goes off. I'm not sure of the schedule or if they are being retro-fitted, but they are certainly now standard on 737NG currently coming off the production line.
The point I am making is that the fact they are being fitted now, must mean that there is an acknowledged problem with the warning horn and its interpretation. Sorry If I'm wording it badly...