How come City didn't have a shirt sponsor on Sunday ? Any reason ?
The official answer is a 125 year anniversary kit. Puma are in their first year, they could have made a huge statement and made that shirt the official home shirt. Everyone would have loved it and it would have been a best seller.
Thing is, they know that the people who buy a new shirt every year will more than likely buy one anyway, whatever it looks like. Likewise the retro shirt will sell loads anyway. So it makes commercial sense to have it as a separate kit. No ideal for the fans, but no one forces them to buy it.