Considering that all of the other figures in that set are from Attack of the Clones and the paint job on the figure is not a shiny metallic finish, I tend to disagree with you and still think it's an AOTC C-3PO...
*Edit*
Ok, I went back to that thread and saw that it's listed as TC-14... My bad, but I still find it strange that they would put a TPM figure in an all AOTC pack...