New members, especially younger generations, prefer to create anew rather than perpetuate the old. Alas, most congregations, in Lyle Schaller's view, wish for young people to act like old people, and blend into the woodwork. But new members often feel like aliens when they join a standing committee of long-term members.
This raises an interesting question. In your church, is there anything new to do? If not, who decides what something new might be? A simple exercise is to ask congregants, "I wish our church could..." This may result in a very engaging list of ministries that newcomers might just claim as their own. Give those new members a long leash.