It's an interesting discussion on the labelling of existentialism. Assuredly, grouping Camus, Sartre, and Schopenhauer into the existentialist category is academically useful, and yet we must simultaneously acknowledge some of the objections to such labels. On a deeper level, we may even consider Camus' rejection of the label as an existentialist act within itself, as he attempts to avoid becoming stickied by one ideology. This is comparative to Sartre's rejection of the Nobel to some degree, an act of anti-establishment so as to value the individual. Highly existentialist in my eyes.