I don't think so. I am here in Wuhan, and the MC assistant is helping the MC to change and update the space schedule. Distribution and promotion on the internet means that there is no list, and messages are sent for the list (some of these MC do it themselves). As you said, rehearsal, usually before the wedding, the MC communicates with the newlyweds in the rehearsal company. On the wedding day, if there is time before the ceremony, some MC will let the assistant and the couple rehearse it again, while others will rehearse it again with the couple themselves. Now most of them are music producers. At the wedding, live music is played for the master of ceremonies. Cooperating with the host is the most important job of the assistant.