The definitive upgrade protocol for TCC is spelled out in Doc ID 1907629.1, here’s the answer:
APPLIES TO:
Oracle Taleo Platform Cloud Service – Connect – Version N/A to N/A [Release 12]
Information in this document applies to any platform.
GOAL
When upgrading the zone what actions are required regarding existing TCC scripts?
SOLUTION
Our recommendation is to upgrade all scripts to the latest version of the Product Integration Packs (PIP).
If this is not possible, then scripts can remain as they are if the PIP version is one Major version away from the zone.
If the difference is greater, test the scripts in staging to determine if they need to be upgraded or not. If an upgrade is needed, make sure to use the latest PIP version in order to prevent having to upgrade them again in the near future.