A piedfort is a wonderful idea!The coin I would really like them to produce, given the fact they seem to be obsessed with the Eagle design is a piedfort/high relief Silver Eagle, like they did with the 2009 UHR gold Eagle.
Getting back on topic, as others have said, I don't think there will be a huge amount of cancellations, as most collectors will keep their order regardless. The canceled orders will most likely be from those hoping to make a fast buck.
As Saltysam stated, my focal point in the set is the reverse proof, so having more regular proofs is not a big deal to me.
Who would think there could be so much drama in an allegedly relaxing and enjoyable hobby like coin collecting.