They could do it though
IF! They balanced the BOM out
So if they Did ONE original theme every TWO years
They could make a Fun pin while generating higher profits .
Then that would help offset the cost Difference for the ONE all out per Yr, and as iceman44 said
People would buy that ...GNR is a great comparison
More than one way to skin a cat so to speak
Will they do it? Probably not,