#3 Matches and Segments are rehearsed
Keeping with the concept that WWE is based on entertainment, it is only normal for matches and segments to be rehearsed. Matches are rehearsed for big events and PPV shows so that everything goes as planned and to make sure that they're performed safely. Superstars will know what to do next and they won't have to keep calling for moves during the actual match. Matches are also rehearsed so that they fit the scheduled time limit and the show doesn't exceed the scheduled time.
Segments are also rehearsed, with superstars learning their promos that are written by the WWE creatives team. Segments are rehearsed so that superstars will know what to do and they won't end up lost during the live segment on TV, which will be very awkward and probably make Vince McMahon pull all his hair out. It is important for segments to be rehearsed so that they don't go against WWE's PG rating. A video of The Undertaker rehearsing his segment with Paul Bearer was uploaded on the internet, however, WWE still doesn't want you to know that matches and segments are rehearsed.