It sounds doable. An AI can be made to keep modifying a game's codebase. I imagine it'd be easiest to separate out a scripting layer for game mechanics & behavior that AI can iterate quickly on, although of course it could more riskily modify the engine itself.

Then you could open voting up to a community for a weekly mechanics-change vote (similar to that recent repo where public voting decided what the AI would do next), and AI will implement it with whatever changes it sees fit.

Honestly, without some dedicated human guidance and taste, it would probably be more of a novelty that eventually lost its shine.