While both of Scott’s Alien prequels had their strengths and weaknesses, one disappointing aspect of Alien: Covenant is that Noomi Rapace’s Elizabeth, the hero of Prometheus, doesn’t return. After surviving the events of Prometheus, Elizabeth certainly proves herself a worthy successor to Ripley, but she’s killed off-screen before Alien: Covenant begins. There’s certainly an argument to be made that Elizabeth’s return would have improved Scott’s divisive prequel film and added to the narrative cohesion between the two movies.
From what’s been shown off from Alien: Romulus so far, Rain could be a new Ripley-like protagonist who returns in potential future films. After two Alien entries in which all the human characters die by the end credits, the franchise has an opportunity to begin a larger arc for Rain in which she grows and evolves over multiple movies. It remains to be seen just how similar Rain actually is to Ripley, but she’s certainly shaping up to be an interesting protagonist for Alien: Romulus.