Yes, the CCC works with new SONAR using a different set of installers. I do not believe the old installers work in the CCC. Cakewalk may also run into problems if they repackage their older products to work in the CCC. It is my understanding there are contractual issues regarding repackaging old releases.
I believe the new SONAR will show up in your product listing too, in a separate area available for download like all of your older products.