I’m not sure if the issue lies on Discourse. The software itself is FOSS.
AFAIK I didn’t saw any limitation on the on-prem edition, so I don’t get it why a company like Mozilla doesn’t have the resources to handle that.
And, even if they are using Discourse’s Cloud infrastructure, it’s not common for services to reach the end of payment without sending a ton of warnings.
Even though you dislike online play, you can still play online with the PS3. Some servers are still up and running, and for other titles there are custom servers created by some fans. And the best part: you don't need to pay the online fee that Microsoft created during the 360 days, which Sony and Nintendo followed after.
Step aside bro, there is a new sheriff in town 😅