To prepare for migrating Google Cloud projects to a new organization node, it's crucial to ensure that the projects' current configurations and dependencies are appropriately managed. The two necessary preparation steps are:

Identify inherited Identity and Access Management (IAM) roles on projects to be migrated (C):

Projects inherit IAM roles from their parent resources. Identifying these roles is essential to understand the permissions and access levels that users have on the projects. This will help in ensuring that after migration, the appropriate roles and permissions are applied correctly.

Remove the specific migration projects from any VPC Service Controls perimeters and bridges (E):

VPC Service Controls provide security boundaries around your Google Cloud resources to mitigate data exfiltration risks. Before migrating the projects, they need to be removed from any existing VPC Service Controls perimeters and bridges to prevent any disruption in access or network communication. After migration, the projects can be added back to the necessary perimeters.

References

Google Cloud IAM documentation

VPC Service Controls documentation