This has (kind of) been done.

Keith Elwin designed his own game (Archer). Stern used the design for IMDN.

Scott Danesi designed his own game (TNA). Spooky used the design to manufacture TNA.

I think Stern (or other pinball manufacturer), as a business, is less interested in ideas than execution. It’s one thing to dream, and another thing to create. If you craft a brilliant design and execute it successfully, there may be interest from pinball manufacturers.

So if you’re interested in being part of that experience, man, build a game!