As someone actually attending this class, the primary reason for this syllabus is to get 2/3 of the class to drop. They couldn't find enough TAs for the class, and were forced to rework the curriculum, as well as get enough people to drop to try to alleviate the overcrowding.
Apparently the housing market there is doing better than much of China's real estate market, but that isn't saying much. The growth of inland cities like Changsa has traditionally been slower than the coastal giants (pretty intuitive) but now with further central government investment, an increased infrastructure the growth is really picking up. The real problem with this building though is that there are increasing costs the larger a building gets from increased maintenance, climate control systems, etc. and it doesn't scale linearly with size. The question here is whether to have one monolithic building or several large buildings. I'd imagine the latter is the better bet, but the cost savings from the modular build may largely outweigh this.
A lot of it has to do with face though. Hunan/Changsha get lots of face projects because they are the home of Mao. Changsha itself is at best a second tier city and not really even on the level as Wuhan or (definitely) Guangzhou that it lies between.
Looking at the designs, the building looks like it will be an eye soar pretty quickly, on par with the Ryugyong.