Whether they call it a Review or something else, it feels like, looks like - an Audit. Before you fill out any forms or run any scripts on your system at Oracle's request, please seek the assistance of a third-party beforehand. The saying: "What you say can be used against you" holds true here and like having legal counsel to represent you - you will want someone to explain the process to you from the Oracle side and give you the confidence to push back.
A third-party can help you understand areas such as:
- Your licensing inventory
- What is installed where
- Understanding metrics
- Virtualization impacts
- Mismanaged fault tolerance
- Unintentional license misuse
Here are some providers:
Palisade Compliance:
http://palisadecompliance.com/oracle-license-audit/
Madora Consulting:
http://madora.co.uk/licence-health-check/
I will list others as they become known. I do not endorse any of these so perform the same due diligence you would when selecting legal counsel.