An owner change is complete only when the incoming person knows the current state and can make the next decision. Identify completed checks, open risks, pending approvals, and the next deadline. Transfer access to the relevant dashboards and documents without sharing credentials in the thread.
Ask the new owner to acknowledge the handoff and run one verification step, such as checking the latest build and rollback contact. Keep the previous owner listed as a fallback until that acknowledgment arrives. If no one accepts the handoff before the release gate, mark the launch paused rather than leaving ownership ambiguous. Update the checklist so later readers see who made the final decision.