The command will not overwrite "C:\Cakewalk Content\Cakewalk Sample Data\Rapture Pro"
As I mentioned above since you moved everything under "C:\Cakewalk Content\Cakewalk Sample Data\Rapture Pro" you can safely delete the "Rapture Pro" folder in "C:\Cakewalk Content\Cakewalk Sample Data"
You must do this before creating the directory junction with mklink