Do we know that for sure? It's possible that the fake 4080 was for yield reasons but the yields are higher than anticipated. May as well sell the same chips for more money and "unlaunch" the shitty product.
This "reverse" has nothing to do with yields, nVidia (rightfully) realized it's better to avoid a shitstorm because this 4080 12GB version is ~30% slower than the "real" 4080.