Philippe realised that the Chestburster title wasn't going to work , if for no other reason that he didn't like the title because it was too on the nose.
At one point it was going to be called Nemesis, and then became Dan O'Bannon's Alien, which he liked as a nod to Frank Pavich's documentary "Jodorowsky's Dune".
Still he wanted a one word title as homage to Alien and at the end of the day, he with his associations started thinking about what this film represented , what it was and how it was a love letter to Dan and so it felt right for him to call it Memory, after Dan O'Bannon's early unfinished script that led to Alien.
At some point along its development, he would go to Diane O'Bannon, the widow of Dan O'Bannon and ask "Do you think Dan would like it?", and in her response she was thrilled
- Another way the film is a love letter to O’Bannon is that you settled on the title Memory, which was the original name of his script. What were some of your alternative titles and how did you land on this one?
Alexandre: That was an interesting journey too. For the longest time, the title was Chestburster, but we knew that ultimately wasn’t going to work, if for no other reason than I didn’t like it as a title. It was too on the nose. At one point, it became Nemesis, and that morphed into Dan O’Bannon’s Alien, which I kind of liked as a nod to Jodorowsky’s Dune. By the way, [director] Frank Pavich is the one who introduced me to Diane O’Bannon, so there’s a huge connection there. But I kept wanting a one-word title as an homage to Alien, and at the end of the day, when we started thinking about that this film represents and what it is and the fact that it’s a love letter to Dan, it felt right to call it Memory. Of course, I went to Diane and asked “Do you think Dan would like that?”, and she was thrilled, so it came together beautifully that way. (https://www.slashfilm.com/alexandre-o-philippe-interview-memory/)