The solution is to convert the sales model to subscription only. If it is clear you are renting it is clear that access is limited.
It’s not great as you’d want to play after end of support, but publishers are not interested for a multitude of reasons. They want a central server for control. Control of gameplay and control of cheaters and control of pirates.
Keeping a server up is implying ongoing work though. At the very least you need someone with domain knowledge to keep it properly online and then also to keep everything up to date and fix stuff like vulnerabilities.
The solution is to convert the sales model to subscription only. If it is clear you are renting it is clear that access is limited.
It’s not great as you’d want to play after end of support, but publishers are not interested for a multitude of reasons. They want a central server for control. Control of gameplay and control of cheaters and control of pirates.