I only ever saw Alien and Aliens. Other than those I never saw the appeal of more of this. The first was an effective Gothic Horror set in the confines of a space ship and the other was a fun action film.
This sounds like a very bad idea. There is this pervasive yet stupid idea in Hollywood that if they get just the right script with just the right cast, in an already bloated (yet mostly beloved) franchise that they can recreate the magic of the originals. It can't happen. Some things need to end for good.