Well, yes and no. Freezing, apparently, disrupts the cell-membranes which leads to serious nutrient-loss once the meat is thawed. However, this process takes time, so if one just thaws the raw meats and then immediately eats them after they are thawed, then that makes little difference. Also, RVAFers seem to report that prefrozen meat tastes less good than nonfrozen meats.
I believe some claim that enzymes are slightly damaged by freezing, and 1 long-term RVAFer even claimed that enzymes get destroyed completely after 10 weeks or more of freezing, I think. Unsubstantiated claims, but let's face it, the science behind enzymes is still little understood even by mainstream scientists, and there is precious little info on the effects of freezing on raw foods.