Someone wants to get $large_sum out of China. They can't do this without raising lots of flags in both countries. So they set up an army of fake borrowers, have them take out fraudulent mortgages on real properties in Canada, pay down the mortgages, and sell the property to obtain clean money on the other end.
All the better if the property rises in value in the meantime due to enormous fraud.
The article explicitly says that the purpose is laundering via professional operators -- see the flowchart diagram toward the bottom of the piece.