This is all pretty ridiculous speculation. It is absolutely correct what they are doing. There is a strict amount that is required in the application guidelines. If you cannot prove you have this amount of money at anytime during the application process, they have the right to reject your application. This is just part of the immigration process. To be honest, we are pretty high risk to the government as a category. They want highly qualified and educated people, that is why they opened the stream, but this category can be high risk, as to be honest it can be very difficult for PhD graduates to get jobs, especially if you have a PhD in an arts or humanities subject for example. They just want to ensure that you have enough money to support yourself for one year once you graduate. They set the bar at a minimum of 2 years to qualify for this stream, but they are really targeting PhD students that are going to be graduating soon and will start paying taxes.