In the summer of 2016 ICAO added Canada and Sao Tome and Principe to the list of countries with "security concerns". Other more safe countries such as Georgia, Kazakhstan, Sierra Leone and Uruguay were added to the list of countries that have adequately addressed their "security concerns".
From what I have heard this is an annual assessment made by ICAO, so provided the government entity in Canada responsible for convincing ICAO that Canada is safer and more secure then Sierra Leone does their job, maybe applicants to China will have better fortune after the fall of 2017.