During the production of the film, Robert Altman's condition was fading and he announced that he had a pacemaker in his heart. For insurance purposes, Big Name Fan, Paul Thomas Anderson was an overseer who would step in as director if anything happened to Altman. As such, the film's themes of "death" can be seen as Altman's own reflection of his mortality.
The fact that he died after production only adds to this.
"The death of an old man is not a tragedy."
Throw It In: When Guy Noir pops the champange bottle, the person who he accidentally hit (offscreen) was director Robert Altman.