From Indiewire via AV Club and Empire Magazine:
As part of Empire Magazine's special "Alien" anniversary issue (via AV Club), the publication confirmed screenwriter John Logan, who co-wrote "Alien: Covenant" with Dante Harper, has already finished writing "Awakening" and the film is now waiting to be made. Empire even spilled the beans on the next sequel's plot.
Following the events of "Covenant," in which it was revealed the android David (Michael Fassbender) caused a genocide on the planet Paradise that wiped out the Engineer population, "Awakening" would find a group of Engineers who survived the mass murder making it their mission to exact revenge and kill David. The Engineers were first introduced in "Prometheus" and are humanity's forerunners. The fight was expected to bring both parties to LV-426, the planet featured in Scott's original "Alien" where Sigourney Weaver's Ripley first encountered the Xenomorphs.
The plot description for "Awakening" indicates Scott was planning to bring the entire franchise full circle with his next installment. Whatever went down in the battle between Fassbender's David and the remaining Engineers would probably give rise to the Xenomorph population Ripley eventually encounters.