I understand not wanting to be completely against this as a concept if it was the best possible way of achieving the desired result, but it is clearly not. First of all, you make a lot of people in those groups, and everyone that is not in one of those groups (multi or biracial people) feel completely alienated which is generally bad marketing.
Additionally, people have already solved the problems that people have different body types and there is no need to reinvent the wheel. I have seen countless silhouettes when selecting clothing that show body, breast, face, hip proportions and shapes for people to select from. Here is but one of many examples:

Finally, this leaves no room for outliers. If you know you have long arms or a long torso, why should you select the race you think would be most similar to your body type. As far as I can tell, there is no simple way to input this information if you know you have ‘atypical’ proportions or have had the same general problem with fit causing you to look for a custom shirt.
If makeup which literally matches skin color does not come in packaging saying ‘asian’ or ‘african’, I really don’t see why shirts should be. This seems like a really lazy way (or perhaps a ploy to stir up controversy and get attention) when you could just get to the heart of the issue directly.