You may create and maintain as many CDBs as you like, each containing different levels of classified data. In fact it is quite straightforward to ‘de-classify’ a CDB that contains sensitive data.
The single-copy data repository description in the press release refers to the fact that the CDB you create can be used as a ‘single-copy’ database for a wide variety of client systems, such as a visual system, SAF/CGF or sensor. If you have created multiple CDBs, your CDB-enabled runtime systems should work with each of your CDBs if you have followed the specification conventions.