In the upgrade of CA Datacom/AD to version 14.0, you will be creating and installing a new MUF, along with all the control, operational and database files. The only files that are not created new are the application database files, which are migrated from the "old" to the "new" MUF in job AXPOR01 (for version 12.0) or AXPOR02 (for r11.0 or earlier), which is available in solution RO63245 (AD 14.0 #15), "CAAXSAMP AXRIM01 AND AXPOR02 JCL MEMBERS MINOR ERRORS" solution.
Consequently, you do not need any additional maintenance on your existing system in order to perform the upgrade to version 14.0.