Well, there's something to say for it. But Jeunet is more an auteur in that sense. He usually choses or writes scripts that are all his from the very start. Alien4 was never that.
It's also interesting to see in all the Making Of's of Alien in the Anthology or Quadrilogy that Alien4 was the only movie that didn't have any studiocrap going on... hehehe... One needs adversity to be great, it seems.