EMR reconfig question - Change custom AMI

My customer would like to know if this announcement https://aws.amazon.com/about-aws/whats-new/2019/05/amazon-emr-announces-support-for-reconfiguring-applications-on-running-emr-clusters/ includes the ability to swap in a new custom AMI for future nodes. My reading of the docs would suggest no but need to confirm.

Your customer could deploy a single node EMR cluster (only 1 master), and configure what your customer want inside this ec2 machine, then build AMI from this master node and deploy other EMR clusters by selecting this AMI.