This is just because the FA's forgot to take the ice cream out early in the service to give it time to soften.

It will melt, you just didnt wait long enough.

I remember reading a scientific paper about this (while waiting for my ice cream to soften on a UA flight) a long time ago. If I recall, it has to do with the ice crystals holding up the fat structure. As the crystals melt, it sweeps away the fat structure and melts. However, if the fat globules get stuck together, then it doesnt get swept away and doesn't melt. There are many other factors but if I recall, this was the largest factor. So it may mean the ice cream has a higher fat content which is generally a good thing (with regards to taste)
At least that is what I can recall