A MAC user in the cloud forum reported that dynamic link is working between his EN CS6 and PR CC. He's starting it from Encore.
I have not loaded CC. Can someone try this and report? MAC and PC?
The possible variables include MAC vs PC (I don't know why, but there was something else, non-encore, where the user could do something on the Mac that PC users couldn't), whether PR CS6 remains on the computer (without it, dynamic link "should" be greyed out), and whether there are problems if the project that is dynamic linked is a CC project.