Not just recognizing the need to, or thinking about a strategy to, or hoping to... but actually successful at attracting new members who are younger than 40.
If not, your congregation needs to start thinking about estate planning in case your congregation dies in the next 25 years. Because it is entirely possible.
Your congregation is aging. It's going to be harder to recruit younger members next year, and the year after that, and so on. Every year the gap between your leaders and the people you need to recruit is going to be wider.
I read somewhere that the average lifespan of a mainline church congregation is 70-some years. From founding to foundering in 70-some years. The pace of cultural change is too rapid for institutional continuity. After a certain number of years, the leaders of the congregation are no longer able to change the institution to accomodate the newer and younger members. So, a slow spiral as the church congregation ages out is almost inevitable.
Money is an excellent preservative, and so a well-endowed institution can go through some long periods of small membership and then recover, but most congregations can't keep going.
So, if it is possible that your church is going to die in the next 25 years, doesn't it make sense to plan for that eventuality?
What is going to happen to your building? Will it be sold? When? After it has decayed and lost most of its value? Where does the money go? Who is going to get "the franchise" -- who will represent Unitarian Universalism in your community when your church no longer does? What comes next? What about the other assets -- the objects of beauty that graced your sanctuary? The hymnals? The library of religious education materials?
There may not be somebody who comes to mind to be your church's heirs.
So the question might be: how does this congregation lay the groundwork for another UU congregation to start in this community? How can it use its assets to get another UU congregation going?