Here is a copy of the new rule book:

2021-Rulebook-Indexed-FINAL-12-17-20

Here are some helpful notes:

Four 2021 Tournament Rule changes:
https://pickleballnexus.com/2020/12/4-rule-changes-in-2021-that-tournament-players-need-to-know/
Five 2021Rule Changes:
https://pickleballnexus.com/2020/12/five-2021-pickleball-rule-changes-that-will-affect-everyone/