Marketplace apps comes with the predefined OS which is customized for the third party software. For example WordPress image comes with Debain OS and WordPress preconfigured. There is no choice to choose from the type of OS.
As I explained most of the Marketplace apps are provided by third party companies one of them is Bitnami so they are the one managing the deployment.
If you are using any of those deployments you need to file a feature request with the company providing that deployment.