Operating ownership
A managed service reduces operational work. It does not transfer accountability.
Name the owners of service configuration, secrets, encryption keys, network approvals, migration jobs, evidence, alerting, incident response and support — before you start, not at handover.
A managed migration service reduces operational work but does not transfer accountability. You still own access, approvals, validation and acceptance of the resulting service. If the deployment model changes what network or migration routes are available, resolve it before the method is approved rather than discovering it during rehearsal.