While attending this year's Sheffield Film and Comic Con, actor Michael Biehn finally opened up a bit about Neill Blomkamp's upcoming Alien 5. Interestingly enough, Biehn revealed that he did speak with Blomkamp about the film, but has not been offered a role yet. He also confirmed that Alien 5 will in fact ignore the events of Alien 3 and Alien Resurrection, as if they "never happened".
Just last month, Blomkamp released a new piece of Alien 5 concept artwork, involving Cpl. Hicks, portrayed once again by Michael Biehn, so it's extremely unlikely that Biehn will be neglected for a role - more likely the Studio and all involved are trying to remain tight-lipped about the project to prevent too much info from leaking out. Not to mention, the return of Cpl. Dwayne Hicks would be a massive hype opportunity for the Studio, so they're probably waiting for the right time to announce Biehn's involvement.
Special thanks to AvPG for the info!
Neill Blomkamp's Alien 5 project was inevitably canceled following the merger between 20th Century Fox and Disney. Blomkamp had hoped to revive characters Hicks and Ripley for a new film, rewriting the Alien timeline, chalking up Alien 3 and Resurrection to mere bad dreams. Studio executives decided to can the project and instead took the franchise in a new direction, tapping Fede Alvarez to direct Alien: Romulus.
Neill Blomkamp's Alien 5 is indefinitely shelved.