Network security should be improved when using automation to push network changes out to network devices, or to change the desired state of overlay networks. It should increase the visibility of changes, as all changes are done from a centralized process, with no exceptions.
Continuous delivery processes, by design, should allow security teams to see clearly which user committed a network change. When a change is pushed to network devices or SDN controllers using the Continuous Delivery process, it will allow easy roll back to a previous version if the security team don't approve of the changes. However, this is still very reactive and continuous integration and delivery processes should include compliance and security checks as part of the continuous integration and delivery process.