According to the opinion of EntertainTheElk
https://youtu.be/sgzH2oRLFTE, and I agree, all good sequels must accomplish five criteria:
1. Give the audience something new
2. Identify what worked and build off of it
3. Change the stakes
4. Play with expectations
5. Add new memorable characters
"Aliens" accomplished all of these, but "Alien³" didn't. Neither did the other sequels and prequels.
Hitting #1 might be difficult, or easy, because the Alien franchise has had numerous sequel pitches since the original. Some of these ideas have already been recycled in the sequels. Prometheus is identical to an old "Alien 2" pitch:
https://youtu.be/S2Dr5LtaQRM. To say nothing of the rejected "Alien³" pitches:
https://youtu.be/lkDrAQWGoR4, "Alien 4: Earthbound", "Alien 5: Red Harvest" and the many, many comics and video games.
There's no scarcity of new settings and alien forms. I'd like to see viral aliens on Anchorpoint. I'd like to see infectious cyborg aliens in smalltown Shitsville. I'd like to see alien experiments loose on Moloch Island. I'd like to see chameleon aliens loose in a monastery. I'd like to see spider aliens scaling down Antartica Station. I'd like to see the Company experimenting with tech from the derelict and creating freak shows. I'd like to see characters visiting a freakish Giger cityscape like in the rejected pitches for Alien 2, Alien 4 and Covenant. I'd like to see a king alien stomping around.
There is so much that could happen.
It doesn't necessarily have to be movies. A CGI cartoon a la "Starship Troopers: Roughnecks" could work. (I don't trust a live action tv budget to do the series any justice, especially after all the awful CGI aliens in the sequels. Practical effects are the only thing that work. If the humans are cgi too then I can still immerse myself.)
But the new producers absolutely need to look out for pitfalls that would ruin the brand. Something like "updating" the franchise with a modern ipod aesthetic is stupid. Retrofuturism is a great idea and helps the series stand out in today's over saturated market.