I imagine it's incredibly useful for prototyping movies, tv, commercials before going to the final version. CGI will probably get way cheaper too with some hybrid approach.

Obviously this will get used for a lot of evil or bad as well

can you imagine a billion dollar company promoting their new pre-vis app?

I feel like that's missing the point of pre-vis anyway, its purpose is to lay down key details with precision but without regard for fidelity (e.g. https://youtu.be/KMMeHPGV5VE), a system with high fidelity but very loose control is the exact opposite of what they want.