There has been a huge lack of left-handed heroes in games. While it is purely an aesthetic feature, it is a beautiful little detail that has been overlooked for years that can make players feel a little more personalized to their liking. Even if it meant making mirror-imaged heroes, I feel this minor detail could put a smile on more of your faithful followers.
If it doesn't make it in the game, I'm not going to complain or whine; I trust your judgement and your focus on more important details and nuances. It is simply a little bit of extra polish to what is shaping into a beautiful game, and it would certainly be appreciated by people in their right minds.