Can these words be anything other than mutually exclusive? I think so but luxury brands will need to dig deep into their history and values to come up with social attributes that will be seen as authentic in the minds of customers and employees. Especially today when corporations that suddenly tout themselves as being socially and environmentally responsible will likely be seen skeptically by stakeholders.
Key factors for success for luxury will include: an in-depth understanding of what matters to customers (this means moving past conventional quantitative market research and talking to customers directly), a strategic, programmatic approach to a relevant and compelling issue (rather than a tactical cause marketing campaign), association with an issue that is highly relevant to employees and customers, a long-term commitment (short-term=low authenticity), and partnerships with non-profits that can add credibility, and a valid means of measuring program impact/outcomes.
Luxury categories that are ripe for an appropriate injection of responsibility include those are particularly conspicuous: jewelry, luxury cars, and designer clothing.