The franchise's "idea" rights belong to Ridley Scott,(More precisely, as far as I understand, after the Alien productions before 2010, Ridley Scott acquired the 'idea' rights of the franchise.) and anyone directing an Alien series or film must satisfy him. He's also the producer of that series and Alien Romulus. Neill Blomkamp also had an Alien 5 project that would erase the history of Alien 3 and 4. At least, until Ridley Scott waved his hand in a camera-focused environment and declared, "You can't make Alien!", Ridley Scott was on the fence about anyone but him making Alien. He's recently changed his mind.