Quoted from spinal:
So you take a car for a test drive, make a deposit and month later the dealership call you and says... "Sorry but the manufacturer couldn't get the power windows to work so put in manual. Oh and AC failed during tests so they just put in a larger fan instead. Oh and it's the same sticker price."
That's not really a fair comparison. Car companies churn out 500,000+ of a model. The car parts you are describing are common, easy to manufacture, and have decades of legacy in their engineering and design. Dealerships just don't have to make calls like this. And if they ever did, it would be without stress. The phone call would contain something like "can we interest you in x model instead?"
Pinball companies churn out a few hundred of any model. It's to a very niche market place. This is a toy with no legacy in engineering or design. If it turns out that what they intended to do at the prototype stage just isn't viable, it just shouldn't lead to armchair outrage by the customers and curious bystanders.