I 100% guarantee the people who wrote that statement don’t know or care how much effort it would take to build the infrastructure to run their server-side components.

I’m fairly confident that any AAA production uses Infrastructure As Code to spin up infrastructure in their dev and qa environments, so it’s literally just a matter of handing over the Terraform or BICEP and some binaries for any custom code they need to use. I also highly, HIGHLY doubt that the vast majority of game servers are hosted on-prem. They’re most likely either using Azure or AWS.