Does WWE wrestlers rehearse their lines before going on air?

Answer 1

Yes its scripted

WWE creative gives them a script or something to follow and the wrestlers put their own piece into it or say what they want to say while following the main point. This is like how the Rock made those famous catchphrases.

Answer 2

They Go over the match like a few hours before the show. They have live events and other shows over the week. They only remember a few spots in the match. they do a lot of improvising.