With a game like this that people have played for 15+ years using the same old reliable skills and builds, It might take a bit of a nudge to get people to try new things. Keeping new items a secret and letting people discover them is fun but new skills should be showcased by the team I think. Relying on players to do it might not work. Especially if the new build is super strong. People might avoid sharing their builds if they think that you might nerf them