Not so sure. PE prices are extremely high owing to the popularity of the class - especially with business passengers whose companies frown on the appearance of true business class and families looking for a better experience. Some corporate travel policies are evolving (especially on transatlantic) which allow lie flat on the overnight sectors but mandating PE on the daylight sectors.

Somewhere I read that airlines are seeing the best profit percentages of any cabin - in premium economy. And some airlines are discussing expanding PE cabins incrementally.