The hypothetical you posed is the actual situation, I am now learning, I have apparently forced on my team. We've ramped up labor 3x revenue preparing product launch in 90 - 180 days. We created an image containing centos 8 , Java , postgres and tomcat a year ago and that what is deployed to beta clients and what we've been testing.
What's ironic is that I sort of went out on a limb with my team by forcing us to go with Linux over Windows and the way I allayed concerns was to ask them to just "wait and see" in hopes that the performance differential would make it a moot point.
edit: after a little thought it seems that moving to RHEL might cost us the least amount of money and downtime. Still sucks and not what we need to be working on right now.