Well at least people will stop saying KP should be dropped for a while.
I think whether you know the score or not when you are in or around the 90's depends on your mindset. I never believe anyone who says they aren't thinking about it though. Last year I played in a (league) game when my score was flashed up as 99 and the captain left everyone on the fence (it was a relatively tight run chase and we needed a few boundries)... It did make life a little easier as I wondered through for the easy single.
Alternatively some people worry about their score and stop thinking about the game so knowing their score helps them. My technique, when the score isn't on the board is to guestimate how many I think I have and minus 10-15 runs from that and I am usually pretty close.
The best solution, but the hardest, is to not think about your own score but to think about the target you are chasing or the target you want to set for the team and the rest should take care of itself.
Whatever KP says, I am not sure that is his method though...!