The use of the phrase "claim the right to be unhappy" here is most indicative of the type of culture that the film created. Emotions are no longer inherent or natural, they are something you must claim or fight for. To have "the right" to something inherently means that it is not simply given. It makes the issue one of possession rather than oppression. It's not that the new society is oppressing the emotions, but rather that they are no longer claiming/possessing them.