Will A Prometheus 3 Ever Happen?
Of course, the question of another sequel comes down to business. While Alien: Covenant made its money back, it was considered a critical and commercial disappointment and earned a lot less than Prometheus. Prior to Covenant's release, Scott teased multiple sequels, but given the response to the film, one final entry to wrap things up seems like the most hopeful outcome. Scott's plan to replace the Xenomorph with A.I. hasn't been terribly well received by the Alien fanbase either, and given the monster's iconic status, it's doubtful the studio would be keen on that direction either.
While Scott will still talk about the project whenever it's brought up in interviews, he's also got a full plate of projects in his immediate future, including Merlin and Queen & Country. There's also the undeniable issue that audiences and fans haven't really warmed to Scott's vision for the prequels, so there may not be much excitement for a third movie. There's already talk of the Alien franchise being given a soft reboot instead of a direct follow-up and given the lack of movement on a Covenant sequel – which was originally set to start filming in 2018 – this seems like the more likely outcome.
What Is The Future Of The Alien Franchise?
That leaves the question of where the Alien series goes from Scott's prequels. Fans would probably like to see Neill Blomkamp's proposed Alien 5, which would have picked up after the events of Aliens and brought back Sigourney Weaver. That project was scrapped to focus on Scott's movies, and Blomkamp has since stated his desire to make the movie has left. If Scott was looking for a marketing ace in the hole, bringing back Ripley in some form would probably do it, but since his prequels are meant to lead into the original, that timeline could prove quite tricky to overcome.
There's also the Fox/Disney merger to consider, with the former selling their properties to the latter. The merger is expected to close in summer 2019, so the future of the series moving forwards will probably fall to Disney. The company aren't known for producing edgier material like Alien or Deadpool, although chief executive Bob Iger has spoken of the potential of producing R-rated Marvel movies, so it’s possible. The Alien brand is also too valuable to be left sitting on a shelf for too long. The future of the series might be given a boost if Shane Black's upcoming The Predator performs well. Fox's two big sci-fi monster franchises are often closely linked, so the success of one usually benefits the other.
If the studio chooses not to continue with the Prometheus/David storyline, there are a number of options. A reboot would likely take things back to basics; an isolated locale with a small number of characters being hunted by a new breed of Xenomorph. On that front, the 2013 game Alien: Isolation could serve as inspiration. The game is considered a canon sequel and finds Amanda Ripley investigating her mother's disappearance 15 years after the events of the original. It's got all the claustrophobic tension of the first film while introducing a potential new heroine for the series.