You must save your After Effects project at least once before you can create a dynamic link from Adobe Premiere Pro or Encore to a composition within it. However, you don’t have to subsequently save changes to an After Effects project to see changes to a linked composition in Adobe Premiere Pro or Encore.

If you use the Save As command to copy an After Effects project that contains compositions referenced by Adobe Dynamic Link, Adobe Premiere Pro or Encore uses the original composition—not the new copy—as its source for the linked composition. You can relink a composition to the new copy at any time.