Joe, I don't think it matters at this point whether they pick country, folk, or a mixture as long as the region of origin is the same. The ISU is not that clear about it in the rules. IMO, they probably should clarify this the next time they have country/folk.
Certainly in 2008, nobody was penalized for music or dance style or even for failing to use movements typical of the style in their elements (which they were supposed to do). It's like the UR and edge penalties in singles-the penalties were in the ISU Communications, but at first the deductions were not taken. Some time, they should either follow their own rules or get rid of rules they are not going to follow.