The shift light is only about economy and saving gas...
As silverton points out, the car's computer monitors the engine load, rpm, and speed. The computer then calculates the most efficient time to shift and turns on the light to let you know you've reached that point. (If you shift before the light, you'll be lugging the engine, if you shift after the light comes on, you're wasting gas).
Since it's all about economy, the shift light will always come on well before you reach red line
I suppose it's technically possible to get the shift light to come on at or near red-line, but that would require a custom reprogram of the car's powertrain control module.