The SVC is only used if your site allows users to modify the RPL concatenation. A lot of sites do not allow the DFHRPL to be modified by the end users since that can cause problems in CICS. The SVC has nothing to do with the batch interface facility. So if your site only uses the DADS batch interface then you do not have to redo the DADS SVC.
The DADS SVC number is stored in the DADS control file. To view the DADS SVC number at a clear screen in CICS if you enter the DADC transaction and press enter you will see the parameters stored on the control file. In my case below I am using SVC 230.
SVC NUMBER ==> 230 230
One problem is EVERY CICS region running DADS has a unique control file. So you would have to check every DADS control file to see what CICS region allows the SVC to be updated.