if you had time to sit and prepare for the pitch, sure, but the video seemed to show the batter getting the info just before the pitcher goes into windup. There's not a whole lotta time to adjust to a pitch at the point, and thats where it can be detrimental to the batter rather then helpful. The only caveat is if the batter is sitting change up the ENTIRE AB and is told when one is coming, THEN he has a huge advantage. A pitcher's windup is more than enough time to prepare for a specific pitch type.