Is the WWE based on a script?
I would say WWE matches and character storylines are based on scripts. It is sports entertainment, not a series of actual sports contests.
Wrestlers, managers, WWE executives, and others on display each have their own characters and usually remain in character while on camera with very specific character behaviors. Occasionally these characters get a complete makeover such as going from “face” to “heel” in order to keep things interesting for the fans. They are sometimes given the opportunity, outside of matches, to act out with a parking lot or locker room fights or confrontations.
Speeches are often given in the ring between matches, to create drama for the audience, to move their story line forward, or to create interest for an upcoming event, sometimes punctuated by acted “violence” or a chair across the back of the distracted speaker.
The matches themselves also have their own scripts which the wrestlers rehearse so they can make it look more realistic, and to reduce the chance of an accident or injury. Some of the men are huge and some of the moves they do with each other can be dangerous, so they need to rehearse or they would make more mistakes and have more career shortening or ending injuries. For a busy WWE wrestler, the constant matches, training, travelling, etc is tough work and hard on the body, sometimes leading to premature death.