Things I like about this: definitively retconning David creating the Alien.
Things I don't like about this: literally every other way this would screw with continuity, not to mention limit the scope of what the show could do.
I'm really hoping this is just "producer speak" akin to "this is the first time the Predators have ever been on Earth" and that they ultimately end up setting it post-Alien 3, because I just can't see any good reason why they'd want to create so many unnecessary problems for themselves - both in terms of ultimately having to make it match up with the films' continuity, but also limiting what they're going to be able to do, and what the audience is going to know has to happen by the end of it - by setting it in the Prometheus era.