The model has been created as an educational tool for children, teaching them about geography, social studies and other subjects. The game world consists of around 4000 billion block, which is the reason given behind the mammoth file size.
Children playing on the build have the option to remove and create building as they see fit, although TNT has been removed so the children will understand to “show consideration for others.”
For Danish readers, the build hasn’t been made public yet, but you can read more about it on this webpage here. Be warned, though, it is in Danish.