Scott didn’t mention who was responsible for writing the Alien: Covenant sequel’s script during said article, but there’s a strong possibility that John Logan is the screenwriter responsible.
There’s little reason to doubt that Scott will be ready to roll camera on the Covenant sequel by next year; the filmmaker himself even reckons he can “keep cranking” out Alien movies for another six years.
Perhaps the bigger question then is which (if any) of the characters in Covenant make it out of the film alive – and will moviegoers approve of how Scott ultimately connects the events of Prometheus with the original Alien?
It’s plausible then that Logan, potentially working in collaboration with Harper, further plotted out where the Covenant sequel will go story-wise, at the same time that he and Scott planned out the director’s vision for the second and third chapters in his Alien prequel trilogy, following Prometheus.