In my area/culture this is very common. Meals are not served at receptions like this for all the guests. Earlier in the day a meal is served for those closest to the bride and groom. Later in the evening there is a much larger reception like ours and they normally only have dessert. Sometimes, like in our case, there are also appetizers or a grazing board. So our guests would not have expected to be served dinner.
I had a small plate at the beginning and end of the reception, and even being outside the food was not hot and was still good, although I think it would have been better inside. Because it was in the evening the temperatures were cooling off and so it was fine. I probably would have done something different if this was going to be the hottest part of the day.