Don't think these plot leaks have been shared here. Not sure if these can be trusted, but if they're accurate, Romulus will need some serious writers to 1) make this not sound silly and 2) reconcile it with the other films.
https://www.avpgalaxy.net/alien-movies/alien-romulus/
Lots of story spoilers started making their way online in March 2024.
We can confirm that the black goo from Prometheus and Alien Covenant (or accelerant as it is known in the expanded universe) is making a return in the film. A Hyperdyne Systems 120-A/2 model android was able to discover and reverse engineer the genetic makeup of the black goo contained within the DNA of the Aliens that had been captive aboard the spacestation. Known in Alien: Romulus as the Prometheus Strain, the scientists had been experimenting with the black goo as a miracle cure for all diseases.
The film will feature an android called Rook who has the likeness and voice of the late Sir Ian Holm which is augmented by AI.
There will be a new weapon that looks similar to the iconic Pulse Rifle. It’s white in colour and the new weapon shares many design elements with the M41A Pulse Rifle including the carry handle, and an underslung pump action.
There will be a connection to the first Alien. Weyland-Yutani actually recovered the Xenomorph that was jettisoned from the Narcissus. It was sent to the Romulus research station. From there, scientists reverse-engineered its DNA and extracted the black goo material which they then used to run their own experiments on – creating their own Facehuggers and Xenomorphs.
Some additional insights here: