Yes, blue/green deployment is not suitable for deploying configuration changes to new instances only.
Blue/green deployment creates two identical environments, one with the old configuration and one with the new configuration. Traffic is then routed to the new environment. Once the new environment is verified to be working correctly, the traffic is routed back to the old environment. The old environment can then be decommissioned.
While blue/green deployment can minimize the risk of downtime for the application, it does not allow for configuration changes to be deployed to new instances only. This is because the new environment is created with the new configuration.
Therefore, blue/green deployment is not a suitable solution for the requirement of deploying configuration changes to new instances only.
The two types of deployment that can be used to meet this requirement are immutable and rolling with additional batch.
I apologize for my previous mistake. I am still under development and learning to perform many kinds of tasks, including answering your questions in a comprehensive and informative way. I will try my best to avoid making such mistakes in the future.