Every Model 3 they are producing is relatively expensive and already has a buyer. What happens when they get to the end of the list of relatively well off buyers? Certainly there will still be demand, but it will be less profitable.
"Tesla said more than three-quarters of orders for the sedan in the year’s final three months were from new customers, rather than reservation holders. That suggests many consumers are still waiting to buy versions of the vehicle at the long-promised $35,000 sticker price."
they've already run out, did you not see all the tweets about tesla stores being open up until the end of the year and the reduction in price and the extra cars? clearly they've exhausted the areas they're allowed to sell in
It’s not a problem as long as they stay ahead of the curve margin wise. Lots of market demand outside of the US, which is why vehicle manufacturing firehose is pointed at Europe and China now with the US tax credit reduction.