It's my understanding that Walmart picked up the tab for these and a slew of post promo developed model kits, solely due to their buying power.
Now that said, I'm sure there's a market for those Classic Cadillacs, as well as '50s Buicks, but I suspect companies are gunshy, because they' don't know the numbers, and they do need numbers in order to get their investment topped with profit back.
BTW are the US modelers prepared to spend $50 for a model kit of "non-muscle" cars, the 250K question