It's all part of TT's plans... They release MP-51 Arcee, everyone spends their money, and then a year or so down the road they release MP-51b which they will market as movie accurate with the correct colors and facial expressions and they'll throw in some additional face plates and some other accessories, charge a bit more and everyone will buy the figure again. They have done it like 3x now with Prime. Twice with Megatron & Bumblebee. Why stop now...
Unlike Prime, Megatron and Bumblebee, I'm not sure Arcee is popular enough for people to buy her twice. Like we never got a better Tracks, did we?