One of the sadder findings of that survey, which was reported in the news, is that millenials are not that religious. According to the survey, "Young adults attend religious services less often than older Americans. And compared with their elders today, fewer young people say that religion is very important in their lives."
As I've written about before, there exists a large group of unchurched and non-practicing young adult Catholics. How do you reach them is the challenge for the Church. Creative thinking and creative evangelization would help. From what I've observed millenials like to go for brunch on Sunday mornings and afternoons. It's difficult getting into a restaurant on Sunday mornings and afternoons in trendy neighborhoods.
One finding that I thought was positive was though they get married later and wait to have children, when asked what was important to them, they replied that being a good parent was very important to them. I guess the hope is that when they become parents they will realize how important it is to raise their children with faith and belief. So perhaps they will embrace religion and religious services as they get older. Let's hope so.