well it's still something you can work on. i doubt they will be letting any of their black cresteds out of their sight any time soon. so if you want one your best bet might be to try to make one yourself.

it's the same with bp morphs. just because one guy made an all white ball python doesn't mean that everyone else gave up trying. and guess what? turns out there was more than one way to make one. good thing they didn't give up.