They're not, and they won't be. This rewrite is a good step forward but it's nowhere near safe enough to be released in the wild. It does however create just enough hype for the true believers to justify to themselves paying $10k for it. Go team elon!
I don't think it's about selling the FSD option now. I think it's the usual Elon strategy of forcing products out the door to accelerate development.
I find this software surprisingly under cooked, but that makes the release more interesting. Does it really miss cross traffic, or would the car slam on the brakes at the last minute? Exciting times.