I maintain that the majority of games are still disposable, despite the occasional subscription model or long-lived hit that pops up. Remember that most games aren't made by AAA studios.

Wasn't Minecraft completely rewritten from scratch in Java after a few years?

And the EA one, like you said, it's just model updates. Very few gameplay mechanics get more than a simple tweak. Just recompile with the new models. You don't need unit tests if the code never changes.